The primary aim of the study is (i) to assess the effect of a soft brace on pain, knee stability and activity limitations. Secondary aims are (ii) to assess the difference in effect of two knee soft braces (i.e., non-tight and tight) on pain, knee stability and activity limitations, (iii) to explore underlying mechanisms of the therapeutic effect of a soft brace and (iv) to assess the late effects of two weeks application of a soft brace on pain, knee stability and activity limitations in patients with knee osteoarthritis (OA). A minimum number of 36 patients with established knee OA, reporting knee instability, will be enrolled from the Amsterdam Osteoarthritis (AMS - OA) cohort.
Patient and clinical characteristics will be assessed at the begin of the measurements including demographics, self-reported activity limitations (WOMAC-questionnaire), NRS pain during the last week, self - reported knee stability during the last three months, muscle strength (Isokinetic Dynamometer) and radiographic severity (K&L grade).
Before walking on the treadmill, knee proprioception (AMEDA), skin sensitivity (Von Frey monofilaments), pressure pain ( hand-held pressure algometer), postural balance and performed based activity limitations (GUG and 10-m walk test) will be assessed. During walking on the treadmill with the application of a soft brace, kinematic data will be assessed for objectifying knee stability. After walking on the treadmill the measurement of proprioception, skin sensitivity, NRS pain, pressure pain, self-reported knee stability, postural balance and performance based activity limitations (GUG and 10-m walk test) will be repeated. Before the second trial of walking on the treadmill with another soft brace, the assessments on knee proprioception, skin sensitivity, pressure pain, postural balance and activity limitations will be repeated. During the second walking trial, knee kinematics will be assessed for objectifying knee stability. After the second walking trial, the assessments from the first trial will be repeated. Patients will be asked to wear the soft brace for two weeks and by telephone knee pain, self – reported knee stability and activity limitations (WOMAC) will be assessed. Additionally, satisfaction and adherence in wearing the soft braces will be assessed.