The association between hip joint and hip muscle control in asymptomatic individuals and individuals with osteoarthritis

The intervention will consist of a passive, sustained stretch at the hip joint. This will be done in one session. The stretch will be performed three times by a clinical researcher. Each stretch will be maintained for 3 minutes. This intervention will be delivered to asymptomatic participants during Phase I, and individuals with osteoarthritis during the Phase II. Participants will receive both interventions (i.e. stretch and active control). Participants will be randomly allocated to a sequence of intervention (i.e. stretch followed by active control or active control followed by stretch). During the stretch, participants will be positioned prone, with their knee at 90° of flexion. The hip will be internally rotated to its maximum range. This position will impose mechanical loading into the hip joint, and it is hypothesized that it will stimulate mechanoreceptors at the hip joint. There will be a 10 minute interval between the two conditions. The following directions will be used for placing electrodes: Rectus Femoris: midpoint 50% on the line from the ASIA to the superior part of the patella. Adductor Longus: four fingerbreadths from the pubic tubercule into the muscle belly – palpate the tendon. Gluteus Maximus: 50% on the line between the sacral vertebrae (midpoint of the base of the sacrum) and the greater trochanter. Biceps Femoris: 50% on the line between the ischial tuberosity and the lateral epicondyle of the tibia. Gluteus Medius: 50% on the line from the iliac crest to the trochanter. Tensor Fascia Lata: On the line from the anterior ASIS to the lateral femoral condyle in the proximal 1/6.