Dynamic movement screens (FMS, overhead squat)

Why dynamic screens matter

A static posture might look fine — but the body might break down the moment it has to move. Dynamic screens reveal mobility, stability, and motor-control issues that static assessment misses.

The overhead squat assessment (OHS)

The most efficient single screen. Tests:

Ankle dorsiflexion
Hip mobility (flexion + rotation)
Thoracic extension
Shoulder flexion
Core stability

Setup: client stands feet shoulder-width, toes forward. Arms overhead, biceps by ears, hands shoulder-width apart. Squat as deep as possible, then return. Repeat 5 times. Watch from front, side, and back.

What to watch for

From the front:

Knees cave inward (valgus) → weak glute medius and/or limited ankle dorsiflexion
Knees bow outward (varus) → tight piriformis or hip external rotators
Asymmetry → unilateral mobility or strength deficits

From the side:

Arms fall forward → tight lats, limited thoracic extension
Lumbar flexion at bottom (butt wink) → limited hip flexion ROM
Excessive forward lean → ankle limitation or thoracic limitation
Heels lift → ankle dorsiflexion deficit

From behind:

Heel asymmetry → unilateral ankle issue
Hip drop → glute medius weakness on opposite side

How to use the findings

Don't try to fix everything at once. Pick the 1-2 most limiting compensations. For each:

1 mobility drill (e.g., couch stretch for tight hip flexors)
1 activation drill (e.g., banded glute bridges)
1 motor pattern drill (e.g., goblet squat with light load)

Re-test in 2-4 weeks.

The Functional Movement Screen (FMS)

A 7-test battery developed by Gray Cook. Scored 0-3 per test:

Deep squat
Hurdle step
In-line lunge
Shoulder mobility
Active straight-leg raise
Trunk stability push-up
Rotary stability

Composite score predicts injury risk in some populations (correlations are real but modest). Many trainers use just the overhead squat unless they're working with athletes where systematic FMS adds value.

Other useful single-screen tests

Single-leg balance — 30 seconds eyes open, 30 seconds eyes closed. Tests proprioception and ankle/hip stability. Single-leg squat — depth and knee tracking on one leg. Tests strength and stability under unilateral load. Wall slide — back against wall, slide hands overhead. Tests shoulder mobility and thoracic extension.

When to refer out

If a screen reveals pain (not just limitation), refer to a physical therapist. Pain is a different category from mobility/strength deficit — pain needs medical assessment.

TL;DR

Overhead squat is the most efficient dynamic screen. Watch from 3 angles. Common compensations trace to specific causes. Pick 1-2 limitations to address — not all at once. Retest in 2-4 weeks. Refer pain to a PT.