Authors (including presenting author) :
Tse TS(1), Hui SH(1), Ho SY(2), Ho YL(2), Ho SH(2), Leung HS(2), Wong CY(2)
Affiliation :
(1)Orthopaedics & Traumatology, Pamela Youde Nethersole Eastern Hospital (2)Prosthetic and Orthotic Department, Pamela Youde Nethersole Eastern Hospital
Introduction :
Many elderlies suffered from knee osteoarthritis. Common treatments include exercise, medication of pain killers, and operation of knee replacement. Not only pain, this degenerative disease may also affect patients’ gait. It is found that OA knee patients would have Lower velocity, cadence and step length (Sadbhawna & Sonia, 2014). They would also have greater trunk lean towards the more painful side and decreased flexion in more painful knee (Creaby, Bennell and Hunt, 2012). Thus, this would cause trunk movement asymmetry in medio- lateral axis (lijima, Eguchi, Aoyama and Takahashi, 2018). The use of lateral wedge orthotic insole had been proposed to be benefit patients with knee varus deformity. The lateral wedge orthotic insole could lateral shift centre of pressure of the ground force and thus reduce the knee adduction moment in OA knee (Roodsari et al.,2017). As a result, it could reduce knee pain.
Objectives :
There are researches proved that the lateral wedge orthotic insole could reduce knee pain but there is limited study which investigate its effect in patients’ gait. The aim of this study is to find out whether it could improve patients’ gait pattern
Methodology :
In this study, 21 OA knee patients with bilateral varus deformity were included. Bilateral customized total contact orthotic insoles with 5-degree full length lateral wedge which fabricated by CADCAM technology were prescribed to patients. Spatio-parameters and trunk movement asymmetry were assessed by using a triaxial accelerometer. Patients were asked to walk at their normal pace on 13m flat ground without any obstacle, with and without the use of orthoses. Data were analyzed to investigate the effect of the orthotic insoles in patients’ gait pattern.
Result & Outcome :
When patients were using the bilateral lateral orthotic insoles, the overall symmetry index, medio-lateral and antero-posterior symmetry index significantly increased (p value < 0.05) which implies patients may walk with less trunk lean and more symmetric gait. Also, those patients mean step length was significantly increased (p value < 0.05). This result shows that the effect of the lateral wedge orthotic insole is quite similar to the effect of TKA according to the study done by Hiyama, Asai and Wada (2020). OA knee patients usually walk with trunk movement asymmetry and this is related to their disability. The Increased trunk asymmetry in medio-lateral axis of the patients may be associated with greater knee pain, disability and quadriceps strength asymmetry (Iijima, Eguchi, Aoyama & Takahashi, 2019). Refer to Chang al (2011), patients increase trunk sway at coronal plane to Lean the trunk laterally over the stance limb so that the center of body mass can be shifted to the centre of the leg. Thus, reduce levers arm and subsequent knee adduction moment (KAM) magnitudes can be reduced. It may decrease the load on the medial compartment of varus knee. This study shows that the lateral wedge insole may have a subtle role in improving OA knee patients’ trunk asymmetry when walking. The significant improvement in medio-lateral (obliquity) trunk asymmetry may be due the reduction in KAM of OA knee with the use of lateral wedge insole. The reduced KAM may reduce knee adduction movement. It may lead to the reduction in functional LLD caused by OA knee and mininmize the loss of propulsion force caused by OA. As a result, there are Significant change in antero-posterior (tilt) trunk asymmetry improvement and step length. To conclude, the lateral wedge insole may improve patients’ gait and to certain extent reduce their disability.
