What the OHSA Measures

The OHSA is a dynamic postural assessment that exposes compensations across the kinetic chain during a functional movement. Because the arms are held overhead while the body squats, it demands mobility and stability from top to bottom at once, and compensations reveal which muscles are likely overactive (short and tight) and underactive (long and weak).

It's a movement screen, not a medical test: it identifies movement-quality patterns to guide exercise selection, not diagnoses. That distinction keeps the tool both powerful and within a trainer's scope.

Setting It Up Correctly

Position the client barefoot or in flat shoes, feet shoulder-width and pointed straight ahead, arms raised overhead with elbows straight so the upper arms frame the ears. Explain and demo the movement first so nerves don't distort the result.

Have the client squat to roughly chair height and return, about five controlled reps, while you observe. View from the front (feet, knees) and the side (lumbo-pelvic-hip complex, shoulders), staying a few steps back so you can see the whole body. Watch the movement, not just the end position.

The Checkpoints, Front and Side

Read the body systematically at defined checkpoints rather than trying to see everything at once.

• Feet (front view): flattening or turning out.

• Knees (front view): caving inward (valgus) or bowing outward.

• LPHC (side view): excessive forward lean, low-back arching, or a posterior tuck ('butt wink').

• Shoulders/arms (side view): arms falling forward out of alignment with the torso.

• Run the checkpoints one pass at a time, feet-and-knees on some reps, LPHC-and-arms on others, rather than trying to catch all four simultaneously.

Interpreting Common Deviations

Each deviation points to probable imbalances. Feet turning out often implicates tight calves (especially the soleus/gastrocnemius) and limited ankle dorsiflexion. Knees caving suggests overactive adductors and TFL with an underactive gluteus medius. An excessive forward lean or arms falling forward frequently reflect tight calves, hip flexors, and lats against a weak core and scapular stabilizers.

Confirm suspicions with modifications: elevating the heels is the classic test, if the forward lean and arms-forward pattern clean up with heels raised, the ankles are a primary driver. These modifications turn a general observation into a specific programming target.

From Findings to Corrective Program

Feed the results into the Corrective Exercise Continuum: inhibit and lengthen the overactive muscles (foam rolling and stretching the calves, adductors, hip flexors, or lats as indicated), activate the underactive muscles (glute and deep-core and scapular work), then integrate the corrected pattern into loaded movement.

The findings also set the starting OPT phase: significant compensations argue for a stabilization-endurance-heavy opening block, while a clean screen supports faster progression. Weave corrections into warm-ups and exercise selection so they feel like training, not homework.

Documentation, Re-Testing, and Scope

Record findings, ideally with video, at onboarding and re-test every four to eight weeks. Showing a client their improved squat pattern is both proof of your value and a potent retention tool, evidence clients can see beats claims they have to trust.

Two disciplines round it out. Communicate findings as opportunities, not defects, so clients feel capable rather than broken. And respect the line: if the movement provokes pain, or the client reports numbness, tingling, or a suspected injury, stop the screen and refer to a physician or physical therapist. For trainers who want to master this, the NASM Corrective Exercise Specialization builds directly on the OHSA.