Which adjustment is NOT recommended for clients with knee and hip injuries that don't tolerate deep knee flexion?

Increasing the height of the footbar is not recommended for clients with knee and hip injuries that do not tolerate deep knee flexion because it can lead to greater strain on the joints involved. When the footbar is positioned higher, the angle of knee flexion tends to be more acute during exercises, which could exacerbate the client's discomfort or lead to potential injury.

In contrast, the other adjustments can provide more supportive alternatives. Lowering the footbar can help reduce the amount of knee flexion required, thereby minimizing stress on the knees and hips. Adjusting the carriage horizontally can also allow for changes in body mechanics that reduce strain. Using a box or peanut reinforces stability and can provide additional support during exercises, thus maintaining safer movement patterns for the client.