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					        Upper Extremities Parts
Shoulder Girdle
Shoulder Joint
Elbow Joint
Radioulnar Joint
Wrist Joint
      Muscle Contribution to Joint
Stronger Muscles = More Joint Stability

Angles of Pull influence Joint Stability

Stabilizing Angles = < 90 angle of pull

Dislocating Angles = > 90 angle of pull
             Shoulder Girdle
Involved in Reaching/Grasping Motions
Designed for Mobility
Unstable joint
Strength of Muscles VERY important
                  Shoulder Joint
Involved in a wide variety of motions
Designed for Mobility, Unstable joint
Rotator Cuff & Deltoids = small angle pull
Wheel-Axle Mechanism
         Overarm Throw Pattern
“cocking action” = extreme lateral rotation

rapid medial rotation and protraction

Strengthen Medial Rotators BOTH
 Concentrically and Eccentrically
                 Elbow Joint
Only Flexion and Extension

Stable joint due to bony structure

Muscle arrangement = stabilizing effect
How to Strengthen Elbow Extensors

Elbow Extensions with
shoulder flexed
figure 2.5e on page 61

Shoulder Hyperextensions
with elbow extended
figure 2.5d on page 61
     3 Ways to Strengthen Elbow Flexors

1.   Elbow flexion from
     anatomical position

2.   Elbow flexion with
     shoulder Hyperextended

3.   shoulder flexion
       figure 2.5j on pg 62 
                  Radioulnar Joint
  Unstable due to weak bony arrangement
  Pronate = turn inward [medial] away from
   anatomical position
  Supinate = turn outward [lateral] back
   toward anatomical position

figure 5.12 left side of picture pronated
page 185 right side of picture supinated
                 Wrist Joint
MSDs - musculoskeletal disorders
    1. angle of the work surface
    2. position requirements of the work
    3. magnitude & direction of applied forces
    4. Degree of repetition
CTS - Carpal Tunnel Syndrome
see Force guidelines per task on page 189
                    Hip Joint
Medial rotation involved in kick, throw & strike
Wheel-Axle - figure 6.5 and 6.6 [page 197]

                         A: medial   B: lateral hip rotation
                  Hip Joint
Bending/Stooping = increase FA resistive
to achieve equilibrium, hip extensors must
 provide high Tension/Force [hams, back]

                              FIG 9-30 page 296
                             “Basic Biomechanics”
                                   4th Edition
                                by Susan J. Hall
                  Knee Joint
• Biarticulate Muscles - work knee and hip
• Muscular Imbalances:
      1. Hams - lateral vs. medial lateralis
      2. Quads - vastus lateralis and medialis
• Positions for potential injury
      1. Foot fixed while hip/trunk rotates
      2. Squats [FIG 6.11 pg 204]
      3. Whip kick in Breaststroke [FIG 6.12 pg 205]
Knee Joint: Potential Injury Positions

                                  page 205
Knee Joint: Potential Injury Positions

                         turning the body
                         while foot is fixed

                          FIG 6.8 page 200
Knee Joint: Potential Injury Positions

                            Deep Squat

                      changing axis of rotation

                           from knee joint
                           calf/thigh area

                      FIG 6.11 page 204
     Knee Joint: Potential Injury Positions
        rehabilitation of knee injuries

page 260: studies on ACL stress, shear forces, petellofemoral contact
                ANKLE JOINT
Bony arrangement = stability
Ligaments play major role in stability

flexion = dorsiflexion
extension = plantar flexion

                  FIG 6.13
                  page 207
             SUBTALAR JOINT
allows foot to navigate uneven surfaces
inversion (sole in) and eversion (sole out)
inversion with plantar flexion
eversion with dorsiflexion

              FIG 6.15
               page 209
    Inversion during Plantar Flexion
        Muscles of Ankle & Foot
Strength important on all sides
Muscular imbalance = misalignment
misalignment = line of g eccentric to joints
weak dorsiflexors may cause shin splints
overdeveloped inversion/plantar flexion muscles
 = prone to lateral ankle sprains
       Stretching Achilles Tendon
Preventative measure for shin splints

Achilles tendon = extension of both
 gastrocnemius and soleus muscles

2 dorsiflexion stretches:
     1. with knee extended
     2. with knee flexed
                Plantar Fasciitis
Overuse Syndrome injury
overload of stress at insertion of plantar surface
 fascia on calcaneous
chronic therapy involves:
     1. Strengthen plantar & dorsiflexors
     2. Increase ROM in dorsiflexion

  see page 210 re Kibler et al study
       Walking               Running

Long support phase       Shorter support phase

always support phase     non-support phase

                          F vertical = 3 x body wt
Ideal Alignments: LEG
   Lower extremities like columns
    supporting a roof

   Ideally as vertically aligned and
    as straight as possible to support
    the forces from above

    FIG 6.19
    page 213
           Ideal Alignments: FOOT

FIG 6.20               a is Ideal
page 214                FIG 6.21
           Leg Length Inequities
Anatomical - due to bone structure

Functional - due to tilted pelvis

Environmental - due to uneven ground
           Femoral                Tibial

Femur rotated medial       Tibia rotated lateral
medial facing patella      lateral facing patella
frequent in FEMALES        frequent in MALES
treatment:                 treatment:
1. Strengthen lateral hip   - muscular balance in all
   rotators                   3 hamstrings must be
2. Stretch medial hip         developed
         INWARD angle
        from proximal to

         lateral   stress is

         medial    stress is
          OUTWARD angle
         from proximal to

          medial    stress is

          lateral   stress is
     Key Features of Good Shoes
Heel well cushioned
Heel Counter firm
Arch Support firm
Sole Width reasonable for stability
Forefoot flexible & cushioned
Toe Box with reasonable room
Traction, Durability, Permeability

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