THE INFLUENCE OF KNEE AND ANKLE BRACING ON LOWER

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THE INFLUENCE OF KNEE AND ANKLE BRACING ON LOWER Powered By Docstoc
					 ISB XXth Congress - ASB 29th Annual Meeting
 July 31 - August 5, Cleveland, Ohio



    THE INFLUENCE OF KNEE AND ANKLE BRACING ON LOWER EXTREMITY KINETICS AND KINEMATICS
                                      DURING JOGGING

        Brian M. Campbell, PhD1, Charles W. Armstrong, PhD2, Daniel Cipriani, PhD, PT3, and James A. Yaggie, PhD, RKT4
                           1
                             Bowling Green State University, Kinesiology Division, Bowling Green, OH
                                2
                                 The University of Toledo, Department of Kinesiology, Toledo, OH
                              3
                               Medical College of Ohio, Department of Physical Therapy, Toledo, OH
                   4
                     San Diego State University, Department of Exercise and Nutritional Studies, San Diego, CA
                                                 email: campbeb@bgnet.bgsu.edu

INTRODUCTION                                                                                        50
There is substantial research on the effects of both ankle and                                      40
                                                                                                                                                                    NB
knee braces on lower extremity kinetics and kinematics, when




                                                                                        Degrees
                                                                                                    30                                                              AB
these braces are worn independently [1,2,3]. However,                                               20                                                              KB
                                                                                                                                                                    A BKB
bracing of the knee and ankle simultaneously, for both                                              10

prophylactic and rehabilitative purposes, is a common practice                                       0
                                                                                                                                      1
in athletics. While prophylactic bracing in athletes may be                                                                 Br ace Condition
beneficial, some research has demonstrated potentially
detrimental effects on lower extremity function. Of particular               Figure 1: Left Knee Position at PKM. p = .007
concern in this regard, are the effects that may be due to the
combined use of ankle and knee braces. It has been                                                  2


speculated that that the mobility limitations induced by                                          1.5

multiple braces may create aberrant motion and forces at other                                      1
                                                                                                                                                                    NB




                                                                                      Nm/Kg
                                                                                                                                                                    AB
joints that may result in injury. Therefore, the purpose of this                                  0.5
                                                                                                                                                                    KB
                                                                                                                                                                    ABKB
investigation was to determine how ankle bracing alone, knee
                                                                                                    0
bracing alone, and ankle and knee bracing together affect                                                0   10   20   30   40   50       60   70   80   90   100

lower extremity kinetics and kinematics during straight ahead                                     -0.5
                                                                                                                       % of Move m e nt Cycle
jogging in healthy subjects.
                                                                             Figure 2: Left Knee Moments
METHODS
Eighteen subjects with no history of lower limb pathologies                 Additionally, although not statistically significant, there were
within the two years prior to this study participated in the                interesting trends in the joint moment data that illustrated a
investigation. Each of the subjects performed a series of                   decreased knee extension moment in the KB and ABKB
jogging trials with each of four brace conditions (no brace                 conditions (Figure 2). Additionally, there appeared to be a
(NB), ankle brace (AB), knee brace (KB), ankle and knee                     reduced ankle joint moment in the AB condition when
brace (ABKB)). An Ankle Stabilizing Orthosis (Medical                       compared to the other conditions. Finally, the ABKB
Specialties Inc.) and the functional knee brace (dj                         condition appeared to evidence a slightly higher peak hip
Orthopaedics, LLC.) were fitted to each subject according to                moment compared to the other conditions.
manufacturers’ guidelines. The subject rode a stationary bike,
at a comfortable self selected pace for 5 minutes to provide a              Previous studies have demonstrated a pattern of knee extensor
period of accommodation to the braces prior to the jogging                  torque adaptation during jogging, associated with FKB use,
trials. Each subject was then required to complete five to                  indicative of reduced stress on the ACL [1,2]. However no
seven trials of straight ahead jogging for each of the                      previous research has addressed the influence of simultaneous
randomized bracing conditions. Gait data was collected using                knee and ankle bracing on lower extremity function. It does
a six camera, 3-D HIRES video system, a gait analysis                       appear from the current results that knee and ankle bracing
software package and two force platforms. This data was                     may be protecting their respective joints, through a reduction
analyzed for each of the subject’s trials to determine the                  in the moments. However these bracing conditions may be
affects of the different brace conditions on the individual’s               predisposing other areas of the body, specifically the hip and
gait pattern.                                                               low back, to potential injury. With the rise in the use of
                                                                            prophylactic combined knee and ankle bracing in athletics, it
RESULTS AND DISCUSSION
                                                                            is important for clinicians to be aware of these possible
Average knee, ankle and hip joint angles for the NB, AB, KB
                                                                            predisposing factors, even though the braces may be of some
and the ABKB groups were calculated and statistically
                                                                            benefit in reducing injury.
compared at the point of peak knee moment (PKM). Figure 1
illustrates a statistically significant reduced knee joint angle at
                                                                            REFERENCES
PKM in the KB and ABKB conditions compared to the NB
                                                                            1. DeVita P., et al. J Biomech, 29, 583-588, 1996.
condition. Results also revealed significantly reduced ankle
                                                                            2. DeVita P., et al. Am J of Sports Med, 26, 778-784, 1998.
joint plantarflexion (p = .046) at PKM in the AB trials and a
                                                                            3. Miller E, et al. P Clin of N America, 37:5, 1175, 1990.
significantly reduced hip flexion angle (p = .034) in the KB
and ABKB trials.


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Description: Jogging is the body movement, not only exercise but also to internal organs and lower limb exercise the major muscle groups. Exercise should choose fresh air, less traffic, ground flat at the time in the morning and evening appropriate. He walked at least every 10 minutes jogging, 5 minutes to run, back and forehead began to sweat that rate. After a period of time may be extended to 20-30 minutes. In the first exercise in the elderly when jogging, walking can be advanced - ran alternately until after the body to adapt and adjust to the whole jogging.