High Knee Against Wall

Stand facing a wall with your feet hip-width apart.

Place your hands on the wall for support.

Engage your core and lift your right knee up towards your chest, while keeping your left foot on the ground.

Quickly switch legs, bringing your left knee up towards your chest and lowering your right foot back down.

Continue alternating legs in a running motion, bringing your knees up as high as possible.

Maintain a fast pace and keep your upper body stable throughout the exercise.

Repeat for the desired duration or number of repetitions.

Losing tension in the core or lower back partway through the movement — because High Knee Against Wall loads multiple joints at once, a small breakdown in bracing at the hips or spine compounds through the whole chain.

Flaring the elbows too wide or letting the hips sag/pike, which shifts load off Cardiovascular System and stresses the shoulder joint.

Rushing through reps using momentum rather than controlling both the lifting and lowering phase, which is especially important since there's no external load to force good tempo.

Skipping a warm-up set at lighter load/intensity — even "beginner" exercises benefit from a rehearsal set to groove the movement pattern before working sets.