During the overhead squat assessment, a client exhibits an excessive forward lean.

In the Overhead Squat Assessment (OHSA), an excessive forward lean often indicates underactive erector spinae muscles along with other potential compensations. The NASM CPT7 Study Guide explains that decreased neural drive (underactivity) in the erector spinae reduces the spine’s ability to remain extended against gravity, leading to a forward trunk angle.

The erector spinae are part of the posterior chain, working synergistically with the gluteus maximus and hamstrings to maintain upright posture during squatting. When they are underactive, other muscles—such as the hip flexor complex—may dominate, pulling the pelvis and torso forward. Popliteus primarily assists with knee stability and internal rotation of the tibia, rhomboids are involved in scapular retraction (not lumbar extension), and the rectus femoris is a hip flexor/knee extensor, often overactive in forward lean cases. Thus, the forward lean points directly to reduced neural drive in the erector spinae.