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EFFECT OF CORONAL-PLANE FOOT CENTER OF PRESSURE MANIPULATION ON HIP JOINT BIOMECHANICS DURING GAIT
S238
Presentation 1487 − Topic 20. Gait and posture
EFFECT OF CORONAL-PLANE FOOT CENTER OF PRESSURE MANIPULATION ON HIP JOINT BIOMECHANICS DURING GAIT Deborah Solomonow-Avnon (1), Eytan Debbi (1), Amir Haim (1, 2), Alon Wolf (1)
1. Faculty of Mechanical Engineering, Technion Israel Institute of Technology, Israel; 2. Department of Orthopedic Surgery B, Sourasky Medical Center, Israel
Introduction Manipulation of foot center of pressure (COP) influences knee mechanics and gait patterns in healthy subjects [Haim, 2008, 2010]. Footwear allowing change in COP may reduce pain and increase functionality and quality of life in knee OA patients by unloading the diseased joint compartment and provoking more normal gait [Haim, 2011]. There is a lack of controlled trials assessing effects of footwear used to treat OA on the hip. The goal of this study was to establish a relationship between specific coronal-plane COP changes and resulting gait parameters associated with the hip in healthy subjects, and to provide a foundation for future study in the hip OA population. We hypothesized that coronal-plane shift of COP would significantly affect gait parameters associated with the hip.
adduction/abduction angle (p=0.005, r=0.81). Peak stance phase adduction angle decreased 106% (p=0.012) from L-COP to M-COP (Table 1).
Add/Abd Angle @ Pk 1 Add Moment Peak Add Angle
L-COP 3.62(3.23)
M-COP -0.56(10.78)
3.88(3.13)
-0.22(10.55)
Table 1: Mean(SD) of coronal-plane kinematics [º] for L-COP and M-COP.
gait
Discussion
Figure 1: COP manipulation was accomplished using a platform in the form of a shoe in which 2 adjustable convex-shaped biomechanical elements are attached to the feet by means of a shoe sole specially designed with 2 mounting rails. One element is located under the hindfoot and the other under the forefoot, enabling continuous positioning of each element in multiple planes.
In accordance with our hypothesis, coronal COP manipulation significantly alters gait parameters associated with the hip. The results may have clinical implications for hip OA. Hip OA patients may walk with decreased external adduction moment, which may reduce load on the joint. In addition they may shift their center of mass over the affected joint in an effort to compensate for weak abductor muscles, better support the load, and avoid pain [Hurwitz, 1997]. These gait compensations may be implemented at a cost of an asymmetric gait that is detrimental to other joints of the trunk and lower limbs [Watelain, 2001]. A decrease in adduction angle was observed with a medial COP and was significantly correlated with decrease in peak one of the adduction moment. Thus, it is possible that a medial COP may provoke a more normal gait by supporting the patient during gait, providing more stability, and reducing pain. In later stages of rehabilitation, it may be beneficial to adopt a lateral COP which may provoke gait that more closely resembles gait of healthy subjects by increasing gait parameters that are decreased due to pathology. This remains to be shown in hip OA patients.
Results
References
Peak one of stance phase external adduction moment was not significant, however adduction angle at the time of peak moment decreased 115% (p=0.008) from L-COP to M-COP. In addition a significant correlation was found between peak one of the adduction moment and the associated
Haim et al, J Biomech, 41:3010-3016, 2008. Haim et al, J Biomech, 43:969-977, 2010. Haim et al, J Orthop Res, 29:1668-1674, 2011. Hurwitz et al, J Orthop Res, 15:629-635, 1997. Watelain et al, Arch Phys Med Rehabil, 89:17051711, 2001.
Methods Ten healthy young males underwent gait analysis in a lateral COP (L-COP) and medial COP (M-COP) condition. COP was manipulated using a novel biomechanical device (Apos System) (Figure 1). Dependence of coronal-plane kinematics and kinetics on COP location was determined using Wilcoxin signed ranks tests (p<0.05).
Journal of Biomechanics 45(S1)
ESB2012: 18th Congress of the European Society of Biomechanics
Presentation 1487 − Topic 20. Gait and posture
EFFECT OF CORONAL-PLANE FOOT CENTER OF PRESSURE MANIPULATION ON HIP JOINT BIOMECHANICS DURING GAIT Deborah Solomonow-Avnon (1), Eytan Debbi (1), Amir Haim (1, 2), Alon Wolf (1)
1. Faculty of Mechanical Engineering, Technion Israel Institute of Technology, Israel; 2. Department of Orthopedic Surgery B, Sourasky Medical Center, Israel
Introduction Manipulation of foot center of pressure (COP) influences knee mechanics and gait patterns in healthy subjects [Haim, 2008, 2010]. Footwear allowing change in COP may reduce pain and increase functionality and quality of life in knee OA patients by unloading the diseased joint compartment and provoking more normal gait [Haim, 2011]. There is a lack of controlled trials assessing effects of footwear used to treat OA on the hip. The goal of this study was to establish a relationship between specific coronal-plane COP changes and resulting gait parameters associated with the hip in healthy subjects, and to provide a foundation for future study in the hip OA population. We hypothesized that coronal-plane shift of COP would significantly affect gait parameters associated with the hip.
adduction/abduction angle (p=0.005, r=0.81). Peak stance phase adduction angle decreased 106% (p=0.012) from L-COP to M-COP (Table 1).
Add/Abd Angle @ Pk 1 Add Moment Peak Add Angle
L-COP 3.62(3.23)
M-COP -0.56(10.78)
3.88(3.13)
-0.22(10.55)
Table 1: Mean(SD) of coronal-plane kinematics [º] for L-COP and M-COP.
gait
Discussion
Figure 1: COP manipulation was accomplished using a platform in the form of a shoe in which 2 adjustable convex-shaped biomechanical elements are attached to the feet by means of a shoe sole specially designed with 2 mounting rails. One element is located under the hindfoot and the other under the forefoot, enabling continuous positioning of each element in multiple planes.
In accordance with our hypothesis, coronal COP manipulation significantly alters gait parameters associated with the hip. The results may have clinical implications for hip OA. Hip OA patients may walk with decreased external adduction moment, which may reduce load on the joint. In addition they may shift their center of mass over the affected joint in an effort to compensate for weak abductor muscles, better support the load, and avoid pain [Hurwitz, 1997]. These gait compensations may be implemented at a cost of an asymmetric gait that is detrimental to other joints of the trunk and lower limbs [Watelain, 2001]. A decrease in adduction angle was observed with a medial COP and was significantly correlated with decrease in peak one of the adduction moment. Thus, it is possible that a medial COP may provoke a more normal gait by supporting the patient during gait, providing more stability, and reducing pain. In later stages of rehabilitation, it may be beneficial to adopt a lateral COP which may provoke gait that more closely resembles gait of healthy subjects by increasing gait parameters that are decreased due to pathology. This remains to be shown in hip OA patients.
Results
References
Peak one of stance phase external adduction moment was not significant, however adduction angle at the time of peak moment decreased 115% (p=0.008) from L-COP to M-COP. In addition a significant correlation was found between peak one of the adduction moment and the associated
Haim et al, J Biomech, 41:3010-3016, 2008. Haim et al, J Biomech, 43:969-977, 2010. Haim et al, J Orthop Res, 29:1668-1674, 2011. Hurwitz et al, J Orthop Res, 15:629-635, 1997. Watelain et al, Arch Phys Med Rehabil, 89:17051711, 2001.
Methods Ten healthy young males underwent gait analysis in a lateral COP (L-COP) and medial COP (M-COP) condition. COP was manipulated using a novel biomechanical device (Apos System) (Figure 1). Dependence of coronal-plane kinematics and kinetics on COP location was determined using Wilcoxin signed ranks tests (p<0.05).
Journal of Biomechanics 45(S1)
ESB2012: 18th Congress of the European Society of Biomechanics