Docstoc

Muscles of Hamstring acting on hip bone, femur, tibia & fibula

Document Sample
Muscles of Hamstring acting on hip bone, femur, tibia & fibula Powered By Docstoc
					INTRODUCTION




   1
       Muscle injuries are common in sports with hamstring injuries being one of the

most frequently encountered.4 Hamstring consists of three muscles Semitendinous,

Semimembranosus and the Biceps femoris. Injury to hamstring is more common in

athletes which often become a problem in chronic conditions.1 Severe hamstring

injury may cause a complete tear called hamstring rapture but majority of these

injuries are first or second degree strains with less than 50% of gross section of the

muscle fibers involved.4


       Reported factors that contribute to hamstring injuries include the lack of

muscle extensibility, improper warm up, fatigue, disproportional quadriceps to

hamstring strength and poor body mechanics during running5. Research shows that

hamstring muscle tightness can play a role in sports related injuries, lumbar spine

disorders & general low back pain.6 Giving vital explanation for importance of

hamstring flexibility.


       Worrel et al5 stated that a lack of hamstring flexibility was the single most

important characteristic of hamstring injuries in athletes. Hamstring strains are likely

to occur during overstriding when close to maximum speed & trying to maintain

speed. During this type of movement, the hamstring muscles are relatively more

stretched than during a stride of normal length at maximum speed although they do

not reach maximum muscle length.3


       Hamstring injuries occur primarily during the high speed or high intensity

exercise and have a high rate of reoccurrence.5 This is often because of inadequate

rehabilitation and premature returns to sport before complete recovery of the muscle

group.1 High reoccurrence rate is also indicated by the fact that the principle risk




                                           2
factor for hamstring injury is a history of previous injury.9 Along with a lengthy

period of increased susceptibility for recurrent injury.7, 9


        Hamstring injuries have been the subject of many epidemiological studies but

despite this there are few agreed risk factors for injury. The most established risk

factors are age, history of injury and low strength measured by reduced hamstring to

quadriceps ratio3. After initial injury highest risk of reoccurrence appears to be within

the first two weeks of return to sports.7 Hamstring mainly undergo eccentric

contractions during sprinting, kicking the ball & picking up the ball during which it

primarily goes for strain.12 As hamstring injuries are most common musculotendinous

injuries5, it could be useful for clinicians to be able to formulate a proper

rehabilitation protocol & developing strategies to institute injury prevention programs.

For this purpose the present project is an attempt to provide as much information as

possible about hamstring injuries.




                                             3
ANATOMY




   4
       The hamstring muscle group is one of the most complex sets of muscles. It

consist of three muscles that span the hip to the knee on the posterior aspect of the

thigh.16 The three muscles are the semitendinosus, semimembranosus & biceps

femoris. As these span from hip to knee they arrive from ischial tuberosity deep to

gluteus maximus & mainly innervated by the tibial divisions of the sciatic nerve. The

short head of biceps does not meet these criteria.14 On the other hand posterior portion

of the adductor magnus is functionally considered a hamstring due to its shared origin

with the other hamstrings and it’s vertical line of pull. It has been postulated that in

man’s earlier evolution the posterior portion of the adductor magnus crossed the knee

joint as well as the hip, lending further credence to its hamstring grouping.16




                                     Semitendinousus

       Semitendinousus muscle is called so because of its long tendon which makes

up almost the entire distal half of the muscle. It blends with fibers of the long head of

the biceps femoris at its origin & then diverges as it passes down the posteromedial

aspect of the thigh to the knee.16


At the site of the attachment the tendon with the tendons of the gracillis & Sartorius

muscles forms a triangular tendinous extension continous with the fascia of the leg.

This extension is called the “Superficial goose’s foot” (pes anserinus superficialis),

under which a synovial bursa (bursa ansernia) is lodged.15




                                            5
ORIGIN                INSERTION                       NERVE SUPPLY   MUSCLE

                                                                     ACTION

From              the Into the upper part Tibial part of the Extend thigh; flex

inferomedial          of         the        medial sciatic      nerve leg &        rotate   it

impression on the surface              of      the (l5,S1,S2)        medially          when

upper part of the medial surface of                                  knee     is     flexed;

ischial tubersity in the tibia behind the                            when thigh & leg

common with the Sartorius              &       the                   are flexed, these

long head of the gracillis.                                          muscles can extend

biceps femoris.                                                      trunk.




                                       Semimembranosus

       Semimbranosus muscle lies under the semitendinosus muscle. It rises on the

ischial tuberosity as a flat tendon which the descends posterior medial and almost the

entire proximal half of the muscle, hence it is called as semimembranosus. The end

tendon separates at the site of attachment into three bands, the pes anserinus

profundus, one of which is attached to the medial condyle of the tibia. Another

attaches to the fascia covering the popiletus muscle, & the third folds over to the

posterior wall of the knee joint and is continous with the oblique popliteal ligament &

                            15
posterior medial capsule.        Additionally, the tendon releases fibrous attachments to


                                                  6
the post horn of medial meniscus that causes the meniscus to draw posteriorly during

knee flexion to prevent impingement.16


ORIGIN                    INSERTION                NERVE SUPPLY       MUSCLE

                                                                      ACTION

From                the Into the groove on Tibial part of the Extend thigh; flex

superolateral             the        posterior sciatic nerve.         leg    &        rotate   it

impression on the surface             of    the                       medially            when

upper part of the medial condyle of                                   knee       is     flexed;

ischial     tuberosity. the tibia.                                    when thigh & leg

Expansions        from                                                are flexed, these

the tendon from the                                                   muscles can extend

oblique       popliteal                                               trunk.

ligament      &    the

fascia covering the

popliteus




                                           Biceps femoris


          It is located near the lateral border of the thigh & is separated from the vastus

lateralis by the lateral intermuscular septum. The muscle consists of 2 heads. The long



                                               7
head (caput longum) arises with the semitendinosus muscle from the ischial

tuberosity; the short head (caput breve) arises from the middle 1/3 of the lateral lip of

the linea aspera femoris & the lateral intermuscular septum of the thigh. The head

fuses & attach to the head of the fibula.15 Distally the two heads have a common

tendon. It also gives off fibrous attachments to the iliotibial band & posterolateral

joint capsule of knee.16


ORIGIN                     INSERTION             NERVE SUPPLY        MUSCLE

                                                                     ACTION

Long head: from the The tendon is either [A] long head, by Flexes               leg      &

inferomedial               folded around or is tibial    part    of rotates it laterally

impression on the split by the fibular sciatic nerve                 when     knee       is

upper part of the collateral ligament. [B] short head, by flexed;                extends

ischial tuberosity; in It is inserted into common peroneal thigh(e.g,                 when

common with the the head of the part                    of   sciatic starting to walk)

semitendinousus, & fibula in front of its nerve [l5,S1,S2]

also from the lower apexor             styloid

part        of    the process.

sacrotuberous

ligament.




                                             8
Short head: From the

lateral lip of the

linea aspera between

the adductor magnus

&      the      vastus

lateralis, from the

upper two thirds of

the   lateral   supra

condylar line & from

the             lateral

intermuscular

septum.




                            Adductor magnus [posterior part]


        It is functionally considered hamstring due to same origin as of hamstring &

vertical line of pull. This is a triangular muscle, forming the medial part of the floor of

the femoral triangle. It lies in the plane of the pectineus.




                                             9
ORIGIN               INSERTION                 NERVE SUPPLY             MUSCLE

                                                                        ACTION

It   arises   by   a The linea aspera in The            main     nerve The          adductor

narrow, flat tendon the middle 1/3 of supply to muscles longus                            are

from the front of the shaft of the of               the    adductor powerful adductors

the body of the femur between the compartment is the of the thigh. They

pubis in the angle vastus medialis & obturator nerve.                   act      mainly   as

between the pubic the adductor brevis The                  adductor synergist              &

crest & the pubic & magnus.                    longus are supplied posterior

symphasis.                                     by   the        anterior controllers during

                                               division    of     this walking.

                                               nerve.                   The         adductor

                                                                        longus helps in the

                                                                        flexion     of    the

                                                                        thigh.




To summarize, the hamstring consist of three biarticular muscles that function as

movers & stabilizers of the knee & hip.




                                          10
Fig: 2.1 Anatomy of hamstring muscle.




                 11
BIOMECHANICS




     12
       The hamstring muscles are primarily biarticular structures which act on both

the hip joint and the knee joint.17 The short head of biceps femoris muscle does not

cross the hip joint and therefore acts uniquely at the knee joint.28 The long head acts

as hip extensor and knee flexor and lateral rotator of knee. Biceps femoris also

functions in lateral rotation of an extended hip, and in adduction of the abducted hip

against resistance. The semimembraneous and semitendenious muscles are active in

hip extension, and also medial rotation of hip, as well as adduction of the abducted

hip against resistance. Flexion and medial rotation of the tibia at the knee are

performed by the semimembraneous and semitendenious.17 The semimembraneous

has the fibers that attach to the medial meniscus that can facilitate posterior distortion

of medial meniscus during knee flexion.28 Being biarticular muscles hamstrings have

no intrinsic mechanism to localize their contraction force to only one joint. The

hamstring muscles, instead contract as a whole, & must rely on adequate stabilization

of one joint by the action of other forces in orders that movement occurs at the desired

point. Such forces might include ground reactions forces & force vectors created by

simultaneous contractions of antagonistic muscles of hamstring group at hip & knee.17

       The efficacy of hamstring in producing force at the knee is dictated by the

angle of the hip joint. Greater hamstring force is produced with the hip in flexion

when the hamstrings are lengthened over that joint, regardless of knee position.28 As

the hamstring acts simultaneously on hip & knee, it can produce either concurrent or

countercurrent motion. Concurrent motion is when there is shortening of hamstring at

one end & a concomitant lengthening at the opposite end, & when the motion at the

knee & hip oppose each other the movement is considered the countercurrent. These 2

conditions create a state of passive & active insufficiency respectively.16




                                           13
       When the two joint hamstrings are required to contract with the hip extended

& the knee flexed at 90degee, the hamstring must shorten over both the hip & knee.

The hamstring will weaken as the knee flexion proceeds because not only they are

approaching maximal shortening capability,but also the muscle group must overcome

the increasing tension in the rectus femoris muscle that is approaching passive

insufficiency. In non-weight bearing activities, the hamstrings generate a posterior

sharing force of the tibia on the femur that increases as the knee flexion increases,

peaking between 75 & 90 degree of knee flexion.28

       During normal gait cycle semitendinouses flexes the knee during swing phase

and semimembransous works primarily as a stabilizes while the foot maintains ground

contract. The short head of the biceps femoris acts during the swing phase of gait

whereas long head of biceps femoris stabilizes the knee when the foot is on the

ground.17 During running, beginning with support phase the hamstrings contract

eccentrically to limit hip flexion and knee extension, followed by brief concentric

contraction. Initially semimembraneous and biceps femoris strike followed by

semitendinous. In the recovery phase hamstrings are relatively silent until forward

swing where semimembraneous fibers eccentrically producing thigh flexion.16




      Fig: 3.1. Muscles of Hamstring acting on hip bone, femur,
      tibia & fibula.
                                         14
ETIOLOGY




   15
       Hamstring strains are more likely to occur as a consequence of competitive

situations where participants are performing in a fatigued condition. Injury will often

happen to athlete who is struggling against a superior opponent. As he becomes

fatigued earlier, movements become strained & tensed as his running speed is

diminished. At some final instance of eversion, the hamstring strain results. Muscle

strength imbalance has been implicated in the literature to be a principle cause of

hamstrings strains. Early reports suggest an optimal muscle strength balance occurred

when the hamstring muscles elicited 50% to 60% of the muscle strength capable by

the quadriceps muscle group.17


        According to researches athletes whose strength ratios demonstrated

hamstring weakness by exceeding the critical level, for example a 3:1 ratio of

quadriceps to hamstrings strength or greater at a knee angle of 120 degree where

considered to be predisposed to hamstring strains. [The critical level corresponds to a

2:1 quadriceps to hamstring strength ratio at a knee angle 120 degree and a 1:1

quadriceps to hamstring strength ratio at a knee angle of 150 degree].


        As we know the biceps femoris muscle has a dual innervations the possibility

of a synchronous stimulation of the two heads exist under certain condition,

stimulation of the biceps femoris muscle could become dissociated, altering both the

action of hamstring muscle group & the coordinated performance of the hamstrings

quadriceps mechanism. Alteration of the hamstring quadriceps function has been

depicated to as the principle mechanism promoting hamstring strains. Biceps femoris

muscle goes for injury even if there is in adequate muscle strength to control the

excursion of the muscle. It suddenly becomes stretched & injury could result.17


Main causes of hamstring strain could be:

                                            16
(1) Fatigue


(2) Poor posture


(3) Poor form


(4) Improper warm up


(5) Overuse or overstress


(6) Abnormal muscle contraction


(7) Improper conditioning


(8) Improper skill pattern.17




                                  17
MECHANISM OF INJOURY




         18
       In order to effectively rehabilitate a hamstring strain and prevent a recurrence

we must establish how and why the injury took place.16 Unusual stress is placed on

the quadriceps and hamstring mechanism at certain points within the range of motion

which suddenly precipitates the injry.17 The resultant injury involves the varying

degrees of tearing to both muscle fibers and supporting connective tissue framework

particularly the blood vessels.17 A review of the literature finds the most authors

agreeing that the hamstring strain occurs at one of the 2 points in the running gait. The

two positions implicated are the late forward swing phase of the recovery and the take

off segment of the support phase.16 The two most common factors in hamstring injury

are lack of adequate flexibility and strength imbalances in the hamstrings flexor-to-

extensor and right-to-left. An imbalance may exist in the muscle strength of

hamstrings between the patient’s limbs and there may also be a decreased ratio

between the flexor [hamstring] and the extensor [quadriceps] groups. A flexor-to-

extensor strength ratio of less than 0.6 or a strength imbalance of 10% or more

between the right & the left hamstring injury.1


       The previous theories contain the common element that the injury is produced

by an excessive external stretch placed on a momentarily released muscle. Muscle

tears are most likely to occur when a rapid maximal contraction is demanded of a

fully elongated muscle which has to overcome increased frictional resistance caused

by the changing the shape of the muscle as the muscle contracts. An important factor

to consider is the speed of the muscle contraction which occurs in events involving

sprinting where hamstrings are common.17 Burkett states that the dual innervation of

the biceps femoris may play a role in the etiology of strains.16 An unequal strength of

the contraction or lack of coordination between the two heads may develop. In view

of the proposed mechanism by which hamstring strain occur, further investigation of

                                           19
muscle spindle activity during sprinting may be valuable.17 Another theory worth

mentioning regarding the mechanism of injury was put forth by Sutton. As stated to

earlier, in order for the hamstrings to function there must be adequate stabilization of

the associated joint. If a quick response contraction is elicited prior to stabilization,

possibly due to uneven terrain or a sudden change in direction of speed, a resulting

strain may develop.16 Other controllable factors such as lack of adequate warm-up,

lack of flexibility,overall conditiong, & the muscle fatigue should all be corrected to

minimize the chance of hamstring injury.1 Injury rate increases in athletes who do not

have adequate opportunity to warm up. In cold or unstretched muscles, lengthening of

the musculotendinous unit with its resultant development of fluid movement within

the structure has not occurred this result in with pain, inhibition of the movement

spasm & swelling.28




   Fig: 5.1 Hamstring muscle strain while playing soccer.


                                           20
GRADES




  21
Hamstring can be divided into 3 grades.


Grade1: There is minimal tissue disruption there by minimal inflammation.25 There is

strain or “pulled muscle” which signifies an overstretching of muscles resulting in

disruption of less than 5% of the structural integrity of musculotendenious unit.1

Patient shows pain on contraction & tenderness.25


Grade 2: There is partial tear with a more significant injury but an incomplete rapture

of the musculotendenous unit1. There is localized swelling and inflammation, marked

by tenderness, muscle spasm, pain on contraction and stretch, brusing later.25


Grade 3: There is a complete rupture of the muscle with severily torn ; frayed ends &

similar to those seen in an acchilles tendon rupture.1 Often there are palpable gaps.

Patients shows marked tenderness & muscle spasm. There is loss of strength &

function, marked swelling and ecchymosis.25




               Fig: 5.1 Grade 2 and 3 of Hamstring muscle.



                                          22
SIGNS & SYMPTOMS




       23
       A minor hamstring strain may produce no physical findings where as a severe tear

may produce extensive bruising. Swelling, tenderness and possibily a palpable defect.

With an acute injury the athlete may be lying on the ground grabbing the back of the

thigh. This is not pathognomic but is highly suggestive for a hamstring injury.1 Table A

shows signs and symptoms of hamstring muscles.


Seveity                     Symptoms                      Signs

Mild [first degree]         Local pain, mild pain on      Mild spasm, swelling

                            passive stretch & active      ecchymosis, local

                            contraction of the involved   tenderness, minor loss of

                            muscle, minor disability      function and strength.



Moderate [second degree]    Local pain, moderate pain     Moderate spasm, swelling

                            or passive stretch and        ecchymosis, local

                            active contraction of the     tenderness, impaired

                            involved muscle and           muscle function and

                            moderate disability.          strength.



Severe [third degree]       Severe pain, disability       Severe spasm, swelling

                                                          ecchymosis, hematoma

                                                          tenderness, loss of muscle

                                                          function, palpable defect

                                                          may be present.




                                         24
PREDISPOSING FACTORS




        25
       There are three factors that predispose the hamstring group to a strain injury

which are muscle loading, muscle integrity & neuromotor recruitment.2 Other

controllable factors such as lack of adequate warm-up, lack of flexibility, overall

conditioning and muscle fatigue can also play the role of predisposing factors in

hamstring injury.1


   (1) Loading of muscle: Hamstring strain presumably occurs when the tension in

       the muscle is sufficiently high may be due to high load resulting in muscle

       fiber failure. According to mann, the largest force occurs as foot strikes the

       ground while muscle contracts concentrically.2


   (2) Effect of mechanics on loading: There are several theories on deficiencies in

       the movement pattern that may predispose to hamstring strain. One is based on

       the stability of trunk. It is thought that with an instable trunk there is

       unnecessary movement of the muscle away from its insertion during

       contraction. The other concept deals with biomechanical parameters. As we

       know gluteus maximus & adductor magnus are powerful hip extensors, so if

       either is deficient there will be increased load on hamstring group. Not only

       weakness at the muscular level but also factor that inhibits the recruitment of

       the correct motor unit plays a predisposing factor. A number of factors may

       affect the load on the hamstring at foot strike. The placement of the foot

       relative to the center of mass will affect the moment that the hamstring must

       produce.2


   (3) Neuromotor attributes of muscle: Altered output in neuromotor system may

       cause inadequate muscle recruitment to deal with the forces applied to the

       hamstring group. As already proved. Where there is muscle irritation there


                                         26
may be changes in motor neuron pool recruitment pattern.2 So if there is

lumbar spine injury it may cause a hamstring strain as a result of an adequate

number of motor units available during maximal contraction.


In addition to these factors; there can be a number of factors which alter

integrity of muscle.


ALTERING INTEGRITY OF MUSCLES:


Following factors alter integrity of muscles.1, 2


(a) Inadequate warm up


(b) Lack of flexibility: lack of flexibility affects normal biomechanics &

   results in strain. It has been also proved that hamstring stretches reduce the

   incidence of injury to it.


(c) Strong eccentric exercises: These can cause microscopic damages to

   muscle leading to increased risk of muscle strain


(d) Increased intensity of training: Rapid increase intensity of training can

   bring about an alteration in muscle integrity which can decrease the ability

   of muscle to withstand stress during regeneration. If training is not reduced

   during this time of vulnerability will occurs.2




                                    27
ASSESSMENT




    28
       For developing strategies to institute injury prevention program and a proper

rehabilitation protocol, assessment plays a vital role in hamstring injuries. Initially

anthropometric data (age, height, body mass, and body mass index) is collected to

ensure a proper protocol design. Clinical indicators assessed were the presence or

absence of:


   1. Swelling.


   2. Visible bruising.


   3. Posterior thigh tenderness.


   4. Pain on resisted hamstring contraction performed with the hip flexed to 30˚

       and the athlete in supine, then with athlete performing isometric knee flexion

       against examiner resistance in two different positions (0˚ and 10˚ of knee

       flexion).


       The knee angle remained fixed during the test and a positive test was recorded

if the athlete experienced pain in the injured area of the posterior thigh. Other clinical

parameters recorded for all injured athletes included maximum pain experienced with

the original injury {measured with a visual analogue scale [VAS] of 0 to 10 [0, no

pain; 10, maximal pain intensity]} and site of muscle tenderness (classified by the

examining clinician). The site of injury was based on the site of maximal muscle

tenderness and recorded by the clinician as being in the upper, middle, or lower

posterior thigh. Convalescent interval was recorded in terms of days lost from

competitive matches.9


       Objective measurements of hamstring muscle length are needed to quantify

baseline limitations and to document the effectiveness of therapeutic interventions

                                           29
both with patients and with healthy people. Clinically, hamstring muscle length is not

measured directly but instead is represented indirectly by angular measurements of

unilateral hip flexion with the knee extended [straight leg raise (SLR) or unilateral

knee flexion after knee extension with the hip flexed to 90˚. Although several tests are

available, the passive SLT test probably is the most common clinical test used to

represent hamstring length.


Straight leg raise with the pelvis and opposite thigh stabilized with straps (SLR-SS):


        The subject is positioned supine and cloth straps were secured over the

anterior superior iliac spines of the pelvis and across the mid-thigh of the left lower

extremity. A left hand is placed over the distal anterior aspect of the right thigh to

ensure that the knee remained in full extension. Then the subject’s right lower

extremity is elevated until firm resistance is felt and the subject confirmed that full

straight leg raise is reached.


Straight leg raise with the low back flat (SLR-LBF):


        The subject is instructed to rotate his pelvis posteriorly and to flatten his low

back against the plinth. The position is checked at the start of the test by attempting to

move a thin ruler placed under the low back. An appropriate number of pillows are

placed under the left thigh to assist with positioning, if the subject could not maintain

a flattened back. Care is taken not to over-rotate the pelvis posteriorly. Then the left

thigh is stabilized with right hand and right lower extremity of the subject is elevated

until firm resistance to further hip flexion is felt and the subject stated the full straight

leg raise has been reached. Close monitoring is done to ensure the full knee extension

was maintained during the test.



                                             30
Straight leg raise with active knee extension (SLR-AKE):


       The subject is placed supine with one cloth strap placed across the anterior

superior iliac spines and another across the mid-thigh of the left lower extremity. Hip

at 90˚ of flexion is maintained so that the wooden dowel on the frame is in contact

with the distal anterior surface of the right thigh to ensure that the right hip remained

at 90˚ of flexion. The subject is asked to extend his right knee actively until

myoclonus is observed. Then he flex his knee slightly until the myoclonus stopped,

thus defining the end point of motion.


Straight leg raise with passive knee extension (SLR-PKE):


       The subject is placed supine with the cloth straps placed as with the active

knee extension test. Again right hip at 90˚ flexion is maintained while moving the

right knee through extension with right hand placed over the distal posterior surface

of the leg. The frame apparatus with the wooden dowel was used to maintain the hip

at 90˚. The knee is extended passively until firm resistance to further motion is felt

and the subject state that maximum knee extension has been reached.11


Flexibility Assessment:


       Hamstring muscle flexibility is assessed with the active knee extension test.

Subjects are placed in a supine position with the anterior thigh touching the crossbar

of a testing apparatus. The hip and knee angles are visually estimated at 90˚. In this

position, a inclinometer is placed 1 inch below and parallel to the fibular head. During

the warm-up procedure, the subjects actively extended a leg four times while

maintaining anterior thigh contact against the crossbar.18




                                           31
MANAGEMENT




    32
                            MEDICAL MANAGEMENT


       Anti inflammatory medication is recommended immediately after injury &

discontinuation after 3-5 days. NSAIDS led to an increased rate of recovery.2

However if used for prolonged period it can interfere with chemotaxis of cells

necessary for laying down new muscle fibers, therefore possibly inhibiting the healing

response.1


                           OPERATIVE INDICATIONS


       Surgery is indicated only after a complete hamstring avulsion from the ischial

tuberosity with a bony avulsion displacement of 2 cm or more.1 Separations of less

than 3 cm are often manage conservatively, requiring 8-12 weeks of rest. Although in

adults complete rapture is rare, this can result from sudden forceful flexion of hip

joint when knee is fully extended and hamstrings are powerfully contracted.


                       PHYSIOTHERAPY MANAGEMENT


       The physiotherapy management of hamstring injury can be divided into 5

phrases.1 This table explains the management of hamstring injury.


                      Time frame        Goals              Treatment

Phase 1: Acute        3-5 days          Control pain & RICE regimen

                                        oedema

                      1-5 days          Limit              Immobilization (brief in

                                        hemorrhage     & extension). NSAIDS

                      After 5 days      inflammation       Pain free passive ROM

                                        Prevent muscle (gentle stretching). Sit on a

                                        fibers adhesions   firm surface with as sock

                                         33
     on the foot as if the foot

     were in the sling. Gently

     pull the towel to bring the

     heel towards the buttocks.

     (2) Hold for 3-5 sec &

     slowly      return     to      the

     starting position.

     (3) Heel slides. Sit on the

     firm, surface with a rock

     on the foot or the towel

     under the heel. Gently flex

     the knee with the foot

     approaching the buttocks,

     then return to the starting

     position.

     (3) Wall slides: lie on a

     firm surface with the feet

     resting on the wall. Slowly

     begin to walk the foot

     down     the   wall,        gently

     increases the knee flexion.

     At the end range slowly

     begin    returning     to      the

     starting position.




34
                    Upto 1 week   Normal gait        Hamstring stretch. Sit on a

                                                     firm surface with a small

                                                     bolster or towel roll under

                                                     the ankle. Place a 3-5

                                                     pound weight on the top of

                                                     the thigh to allow a passive

                                                     stretch of the hamstring

                                                     muscle.

                                                     Use crutches if needed.

Phase 2. Subacute   Day 3> 3 wk   Control pain & Ice, compression & electric

                                  oedema             stimulation

                                  Full       active Pain free pool activities

                                  ROM                Pain free passive & active

                                  Alignment     of ROM

                                  collagen           Pain      free   submaximal

                                  Increase           isomerics: sit on a firm

                                  collagen           surface with the involved

                                  strength           leg in slight flexion & the

                                                     heel on the mat. Push the

                                                     heel into the firm surfaces

                                                     & then pull towards the

                                                     buttocks. It is important to

                                                     note      that   no   actual

                                                     movement of the extremity

                                                     occurs only a hamstring


                                   35
                                           muscle contraction. Hold

                                           the relaxation for 5 sec and

                                           then relax.

Phase         3: 1-6 wk   Acute phase 2 Ice and compression

Remodelling               goals

                          Control pain & Ice and electric stimulation

                          oedema

                          Increase         Prone concentric isotonic

                          collagen         exercises. Lie prone on a

                          strength         firm surface with a pillow

                                           under the hips to increase

                                           hip flexion. Place a cuff

                                           weight on the involved leg

                                           and flex the leg to bring

                                           the   heel     towards      the

                                           buttocks.     Perform       the

                                           flexion movement slowly,

                                           then return the leg to the

                                           starting position.

                                           (2)   Standing       concentric

                                           isotonic exercises: stand

                                           near a table or wall for

                                           support place a cuff weight

                                           on    the     involved     leg.

                                           Keeping the knees aligned


                           36
                                                       flex the involved leg to

                                                       bring the heel toward the

                                                       buttocks      in   a     slow

                                                       controlled manner return

                                                       the leg to the starting

                                                       position.

                                                       (3)   Isokinetic    exercise:

                                                       Must be performed at a

                                                       facility with the proper

                                                       equipment. Lie prone on

                                                       the table with a stabilizing

                                                       strap. Placed across the

                                                       hips. The involved leg will

                                                       also have a stabilizing

                                                       strap placed across the hip.

                                                       The involved leg will also

                                                       have a stabilizing strap

                                                       placed across the hip. `



Phase 4: Functional   2 wk- 6 month   Return to sport Walk/ jog. Jog/sprint sport

                                      without reinjury –specific skills & drills {

                                                       slide 4 board, lateral drills)

                                      Increase         Pelvic      tilt   hamstring

                                      hamstring        stretching sit on the edge

                                      flexibility.     of the chair with spine in


                                       37
                                                          neutral       position.   The

                                                          involved leg is straight

                                                          with the heel resting on the

                                                          floor and the toes          in

                                                          dorsiflexion. Keeping the

                                                          spine        straight,    lean

                                                          forward, bending at the

                                        Increase          hips. A stretch will be feet

                                        hamstring         along the posterior aspect

                                        strength.         of the leg

                                        Control pain      Prone        concentric   and

                                                          eccentric exercises.



                                                          Modalities ; NSAIDS are

                                                          needed

Phase 5: Return to 3 wk- 6 month        Avoid reinjury    Maintaince stretching and

competiton                                                strengthening.1




The exercise therapy plays a vital role in management of hamstring injury. During the

acute phase appropriate manual therapy techniques should be implicated. The

functional rehabilitate program is commenced as soon as athlete is able to jog without

pain.2 Few exercises are recommended which are following:




                                         38
(A) Stretching after injury:


           In the acute phase, pain free range of motion is achieved.2 Stretching to

   avoid loss of flexibility is an important component of the post injury treatment

   PNF stretching can be as well used. Gentle active stretching is used initially

   followed by passive static stretching as pain allows.1




         Fig: 9.1. Self Stretching of Hamstring muscle.




(B) Massage therapy :


           Soft tissue techniques can be used as well for the treatment of

   hamstring strain. The distal musculotendinous region is palpated & treated in

   knee flexion with the foot resting on the therapist’s shoulder. Transverse

   friction, transverse gliding and sustained myofascial tension are used.2




                                      39
(C) Manual therapy :


           In case of presence of a degree of hypomobility in any segment of the

   lumbar spine should be treated with manual therapy. If increased neural

   tension is found neural stretches should be induced.2


(D) Strengthening :


           It is an essential component of prevention and rehabilitation of

   hamstring injuries. Muscle strengthening should be specific for deficits in

   motor unit recruitment, muscle bulk, type of contraction and ability to develop

   tension at speed.2


           In hamstring injuries due to limited motion, isometrics are initiated

   first, using submaximal isometric contractions, with improvement in motion &

   pain, the isometric exercises are replaced by isotonic exercises with light

   weights. When there is pain free ROM, a high speed low resistance isokinetic

   exercise program is begun.1 Isokinetics have been described for screening

   diagnosis and treatment of hamstring strains.2


           There are several elements that a hamstring rehabilitation program

   should include to ensure a successful return from injury. Primarily it should be

   safe but it should also be designed to increase loading gradually in a

   systematic progressive fashion. The program should be designed to create a

   smooth transition between the completion of program and the subsequent

   return to full training and completion. The table (a) shows recommended

   regimen for hamstring training.2




                                      40
Weight          Load         Reps      Sets         Rest      Speed           Regularity

Motor      unit 60 RM        15        6            time      Concentric      3 per day

recruitment                                         30 sec    2         sec

                                                              eccentric 2

                                                              sec

Strength        6-8 RM       6-8       3-5          2 min     Concentric      Once    per

                                                              1         sec 1-2 days

                                                              eccentric 3

                                                              sec

Hypertrophy 8-12 RM          8-12      6            2 min     Concentric      Once    per

                                                              1         sec 1-2 days

                                                              eccentric 3

                                                              sec

Power           40 RM        15        3-4          3-4 min   Quick with Once         per

                                                              control         2-3 days2.




         Table (a) regimen for hamstring training


                As there must be gradual progression between the different elements of

         the rehabilitation program, the type of strengthening program that can be

         performed for hamstring injuries is dependent on the severity of injury.2 Now

         this table (b) depicts the type of strengthening program according to grades of

         hamstring injury.




                                             41
Grade                         Time                         Exercises

1-2                           3 weeks                      Light neuromotor

2-3                           4-6 weeks                    Neuromotor strength

                                                           Deceleration

3 or post surgery or to 6-12 weeks                         Neuromotor strength

correct marked weakness                                    Deceleration

                                                           Bulk

                                                           Hip strength2

        Table (B): Strengthening program


               For overall rehabilitation of an athlete not only should the hamstring

        itself be considered but the muscle that assists its activity should be

        emphasized. Gluteals and adductors magnus strengthening should be included

        for their proper conditioning. Strength and stability of pelvic complex is also

        an important aspect as excessive movement of pelvis can increase loading on

        hamstring. Core stability plays an important role for this hip strengthening

        exercise such as one –legged bridging, squat, split squat, prone eccentric

        exercises, wall leg exercises can be induced2. Pool walking and stationary

        bicycle with no resistance are also used; mainly in early stages.1,2 For an

        athlete hamstring conditioning protocol is proceeded after recovery of injury.

        This table (C) shows hamstring rehabilitation program for athletes.




                                           42
Fig: 9.2. Strengthening of hamstring muscle.




                       43
    Table (C): Hamstring rehabilitation program for athletes.


HAMSTRING REHABILITATION PROGRAM

  1. 2 km jog

  2. 2 km varying pace up to 75% of maximum

  3. Run through : accelerate 40 m, constant speed 20 m (time 3.5 sec), decelerate

     40 m (*3)

  35 m        20 m     35 m (*3)

  30 m        20 m     30 m (*3)

  25 m        20 m     25 m (*3)

  20 m        20 m     20 m (*3)

  15 m        20 m     15 m (*3)

  (4) Run through: accelerate 40 m, constant speed 20 m (time 2.5 sec), decelerate

  40 m(*3)

  35 m        20 m      35 m (*3)

  25 m        20 m      25 m(*3)

  20 m        20 m      20 m(*3)

  15 m        20 m      15 m(*3)

  10 m        20 m      10 m(*3)

  (5) Running out to catch ball- uncontested (*5)

  (6) Running out to catch ball- contested (*5)

  (7) Running out and picking up ball- contested (*5)2.




                                        44
PREVENTION




    45
          It is very important to follow prevention measures for hamstring muscle

injury. Strength imbalance, lack of adequate flexibility, lack of adequate warm-up are

some of the factors which is very important in the prevention of hamstring muscle

strain.


There are some exercises which can be done to prevent hamstring strain.1


HAMSTRING STRETCHING REGIMEN


    (a) Single –leg hamstring stretch:


          Supine with both legs flat on the table. Loop around the foot and hold the ends

    of the towel in your ends. Keep the knee straight and the foot in position (pointing

    towards the ceiling). Pull the leg up the ceiling pull until you feel a stretch in back

    of and sustain the stretch for 30 seconds. Relax and repeat


    (b) Straddle groin & hamstring stretch:


                 Sit on the floor with both legs straddled. Keep knees straight with knee

          cap facing the ceiling & feet in the dorsiflexion( pointing the ceiling). Be sure

          to keep your back straight & bend forward at the hips. First reach straight

          forward until you feel a stretch in the hamstring and sustain the stretch for 30

          seconds. Relax and reach to the right until a stretch is felt and held for 30

          seconds. Relax and reach to the left.1


          HAMSTRING STRENGTHENING REGIMEN


          (a) Injury prevention:




                                              46
        Hamstring strengthening exercises are also used to the quadriceps –to-

hamstring ratio and any asymmetrical between the hamstrings of the right &

left legs.


   (b) Prone hamstring curls


       Place an ankle weight on the involved leg. Lie prone, placing a pillow

under the involved knee if needed. With the foot in position as shown in the

photo, bring the heel towards the buttocks in a slow, controlled manner, begin

with one set of 12 to 15 repetitions & progress to 2 to 3 sets of 12 to 15

reptitions.1


(C) Hamstring curl machine:


        The exercise can be performed on a prone or a standing hamstring

machine. The weight will be at the ankle. Curl the leg against resistance by

bringing the heel towards the buttocks. Begin with one set of 12 to 15

repetitions & progress to two to three sets of 12 to 15 repetitions.1




                                    47

				
DOCUMENT INFO
Shared By:
Stats:
views:77
posted:4/26/2012
language:English
pages:47
Description: Muscle injuries are common in sports with hamstring injuries being one of the most frequently encountered.4 Hamstring consists of three muscles Semitendinous, Semimembranosus and the Biceps femoris. Injury to hamstring is more common in athletes which often become a problem in chronic conditions.1 Severe hamstring injury may cause a complete tear called hamstring rapture but majority of these injuries are first or second degree strains with less than 50% of gross section of the muscle fibers involved.