Final answer:
Instruct the client to hold the right knee in a flexed position to properly stretch the right peroneals. This position allows the peroneal muscles to lengthen effectively and reduces tension during the stretch.
Step-by-step explanation:
To properly perform a stretch for the right peroneals, one should instruct their client to hold his/her right knee joint in a flexed position (Option A). The peroneals, which are located on the outer part of the lower leg, are best stretched when the ankle is dorsiflexed (toes pulled towards the shin) and the foot is everted (sole turned outward), with the knee bent. This reduces tension on the muscles and allows for a more effective stretch.
The position of the knee is essential because a flexed knee allows the peroneal muscles to relax and lengthen without the interference of tension that would be present if the knee were extended. To enhance the stretch, it is often recommended to be seated or in a position where the weight is off the feet, ensuring that the peroneals are not under undue strain.