The wall sit, also known as 'wall squat' is an exercise to strengthen your thighs and glutes. It primarily targets the quadriceps, the front of the thigh, but it will also work your hamstrings, glutes, adductors, calves and core.
This is an isometric exercise in which you need to hold the same position for as long as possible, keeping the tension on your muscles the whole time, this works muscle endurance and mass.
The wall sit is a great exercise for beginners, it is very simple to learn, and the wall will keep your back in a straight position decreasing the risk for the lower back injuries that are so common when training.
This exercise is also great for you if you don't have much time to workout, it does not require any weights and can be done easily at you home or office, A wall sit of just a minute or two will work your entire lower body.
Your knees should never extend past your feet, keep the knees directly above your ankles.
If you feel pain in you knees immediately stop the exercise. Although being less taxing on the joints for most people, this exercise might still put a lot of pressure on your knees, don't do it if you feel knee pain, this might lead to injury. Check if your form is correct, or move your back a little upward to decrease the stress on the knees. If you still feel pain, this exercise might not be a good fit for you.
A drawback of an isometric exercise is that it only strengthens the muscle in the angle in which you hold the position. To overcome this, hold your thighs in different angles each time. Slide your back a little more down or up to work a different angle, just don't lower your hips below the knees, it will put unnecessary pressure on the knee joint
Hold your back against the wall. Maintain a neutral curve in your spine, keep the shoulders flat on the wall.