Strengthening the quadriceps in the presence of knee pain, chondromalacia or arthritis can be challenging. Often, clients cannot tolerate traditional lunges or loading due to pain in certain parts of knee flexion on descent or extension on ascent. In these cases, isometric strengthening using time under tension can be an effective alternative. This exercise is a progression from the wall sit discussed in the prior column.

Execution: Stand in a split stance position with the left leg forward. Lower down to a comfortable position and hold for 30 seconds. Return to upright and change positions so the right leg is forward. Repeat the same technique and hold time. Perform 2-3 sets on each leg.

Beyond strengthening, the goal of this exercise is also to maintain dynamic stability and proper alignment of the front leg by not allowing the femur to internally rotate or the hip to adduct toward midline. Keep in mind that the step length or distance the font leg is forward should be adequate enough to prevent the knee from moving over the toes on descent.

1. Increase the hold time (more time under tension)
2. Increase external load by adding a weight vest or having the client hold dumbbells
3. Perform a rear foot elevated isometric split squat with upper body support
4. Perform a rear foot elevated isometric spot squat without upper body support
5. Perform a rear foot elevated isometric split squat without upper body support and external load

Regression: Use upper body support on the floor if balance with the isometric split squat is a concern

Application: This exercise is an effective way to improve quadriceps and hip strength in the presence of knee pain or joint dysfunction that may prohibit traditional loading progressions. It can serve as a precursor to more conventional exercise, as well as using the time under tension principle to elicit positive physiological change. In addition, it also facilitates better proximal stability which will help optimize neuromuscular control and promote proper movement patterns.