The Efficacy of Unilateral Speed-upscaling Gait Training in Promoting Pain and Functional Recovery in People With Total Knee Replacement: A Randomised Controlled Trial

Knee osteoarthritis (OA) is the most common form of arthritis and is the leading cause of chronic musculoskeletal pain and functional disability. Gait assessment is essential for the rehabilitation of people with knee OA. It may reflect the impact of knee OA on functional outcomes and allow prediction of prognosis for patients. Various people with knee OA may demonstrate different forms of gait asymmetry owing to his/her own knee pain experienced and joint instability perceived. The stance time, peak vertical and peak propulsive ground reaction force have found to be significantly reduced on the OA affected limb. People with knee OA demonstrate compensatory gait pattern to minimize joint loading. It is quite common that the severity of the OA symptoms varies in the two knees, and patients may demonstrate various forms of gait asymmetries, such changes in gait biomechanics does not only impact the affected knee joint. Its impact extends proximally along the kinetic chain system of the human body, where often knee OA patients presents with significantly increased lateral trunk flexion towards ipsilateral limb during walking.

Gait asymmetry as a result of knee OA has been constantly reported in both human and animal studies. Previous studies showed that people with unilateral knee symptoms may adapt to asymmetrical movement patterns, which results in reduced net knee extension demand moments Research interest on gait asymmetry has been expanded to other cohort of patients, e.g. hemiplegic stroke patients. Extensive evidence has shown that the modification of walking speed has a positive impact on the propulsive force of hemiplegic patient's affected limb. These encouraging results have form indications for future investigation on evaluating the impact of innovative gait training in promoting symmetrical gait pattern, targeting patients with unilateral knee OA or bilateral knee OA of different severity. The objective to assess knee OA's gait under different walking conditions is now feasible with the access to the dualbelt treadmill at PolyU. In addition to walking speed modification, emerging backward walking as part of gait training rehabilitation in knee OA patients has become increasingly popular. Backward walking is regulated by the same central pattern generator as forward walking; however, it does not require initial heel contact in early stance phase of the gait cycle as it would be in forward walking. This leads to reduced compression force at the patella-femoral joint and decreased force absorption imposed at the knee joint. Recent systematic review and meta-analysis have suggested combining backward walking to conventional physiotherapy has significantly improve clinical outcomes, including pain control, functional disability, muscle strength, gait pattern, balance and postural stability in knee OA patients.

All of above-mentioned findings have highlighted the connection between specific gait parameters and clinical outcomes, and also the importance of monitoring these changes as disease naturally progress. It is also vital to note the benefits of emerging technologies as the implementation of novel strategies can optimize the ambulatory capacity of the individual, which therefore enhance their recovery potential and quality of life.