Is manual therapy for stiff knees using lessons learned from 4D motion analysis more effective than traditional manual therapy?

INTERVENTION: Knee Mobilization to increase knee flexion ROM. Grade 3 Posterior‐Anterior (PA) joint glide with medial rotation performed on stiff knee performed at a dosage of 3 x 30 oscillations. Participants will undergo 4 face‐to‐face physiotherapy treatment sessions (1 x 1 hour and 1 x 30 minutes during the first week, and 2 x 30 minutes during the second week). This intervention will be delivered by either a registered physiotherapist or a student physiotherapist under the supervision of a registered physiotherapist. Participants will also be given a home exercise program of a self‐mobilization in the direction of treatment (PA). This will will be performed with the patient in supine, a towel roll positioned in the knee crease and a towel around the ankle, pulling the knee into maximal passive flexion and oscillating for 10 seconds. Participants will be asked to perform this 2o times, twice a day and will be asked to complete a logbook to assess adherence to the home exercise program. CONDITION: Stiff Knees PRIMARY OUTCOME: Knee flexion range of motion (ROM) using a digital goniometer (Dualler IQ, JTech medical, Utah). SECONDARY OUTCOME: Knee pain rated using the Numeric Rating Scale (NRS). Patient perceived function and knee‐related quality of life using the Knee Specific Outcome Score (KOOS). Patient perceived function using the Patient Specific Functional Scale (PSFS). INCLUSION CRITERIA: ‐ Individuals with restricted knee flexion ROM ‐ Aged >18 ‐ Stiffness duration of at least 7 days