Abstract
Medial knee OA effects approximately 4.1 million people in England. Non-surgical strategies to lower knee joint loading is commonly researched in the knee OA literature as a method to alleviate pain and discomfort. Medial knee OA is much more prevalent than lateral knee OA due to the weight bearing line passing medial to the knee causing an external knee adduction moment (KAM). Numerous potential gait retraining strategies have been proposed to reduce either the first and/or the second peak KAM, including: toe-in gait, toe-out gait, lateral trunk lean and medial thrust gait. Gait retraining has been researched with little regard to the biomechanical consequences at the hip and ankle joints.
This systematic review aimed to establish whether gait retraining can reduce medial knee loading as assessed by first and second peak KAMs, establish what are the biomechanical effects a reduced KAM has on other lower limb joint biomechanics and outline patient/participant reported outcomes on how easy the gait retraining style was to implement. The protocol for this systematic review was registered with PROSPERO on the 23rd January 2018 (registration ID: CRD42018085738). 13 databases were searched by one author (J.B.B). Additionally, PROSPERO was searched for ongoing or recently completed systematic reviews. Risk of bias was assessed using the Downs and Black quality index.
Search: Group one consisted of keywords “walk” OR “gait”. Keywords “knee” OR “adduction moment” built up the second group. Group three consisted “osteoarthriti” OR “arthriti” OR “osteo arthriti”, OR “OA”. Group four included “hip” OR “ankle”. the searched results of each group were combined with conjunction “AND” in all fields.
Out of the eight different gait retraining strategies identified, trunk lean reduced first peak KAM the most, which was evaluated in 3 studies, reducing first peak KAM by 20%-65%. There was a lack of collective pelvic, hip and/or ankle joint biomechanical variables reported across all 11 studies. Of eight gait retraining styles identified, the strategy that reduced first peak KAM the most was an increased lateral trunk lean, which was evaluated in 3 different studies.
This is the first systematic review that has highlighted that there is limited evidence of the biomechanical consequences of a reduced knee joint load has on the pelvic, hip and/or ankle joints when undertaking gait retraining protocols. Future studies assessing gait retraining strategies should provide biomechanical outputs for other lower limb joints other than the knee joint, as well as providing participant perceptions on the level of difficulty the gait style is to perform.
