Flexibility vs mobility
Flexibility — the passive range of motion at a joint. How far you can be moved. Mobility — the active range of motion you can move through under control.A client might have great hamstring flexibility (legs can be passively raised to 90°) but poor active mobility (can't actively lift the leg past 60°). The gap is strength through ROM — the most common limitation.
Most "mobility work" actually targets active range through eccentric loading and end-range strength — not just passive stretching.
The 5 joints to assess
1. Ankle dorsiflexion — most clients are limited here. Test: knee-to-wall test. Stand facing wall, foot ~4 inches back. Try to drive knee to wall without heel lifting. >5 inches = good. <3 inches = limited. 2. Hip flexion — for squat depth and many lifts. Test: supine, raise leg straight up. Goal: 90° (knee passes vertical) without low back lifting. 3. Hip external rotation — for squat stance, athletic positions. Test: seated 90/90, knee out to side. Test passive ER and active ER from there. 4. Thoracic extension — for overhead lifts and posture. Test: lie on foam roller mid-back, arms overhead. How far can the head reach toward the floor while ribs stay down? 5. Shoulder flexion — for overhead pressing and pulling. Test: lie supine, arm reach overhead. Wrist should touch floor without rib flare or low back arching.How to write what you find
For each joint: "Limited" / "Adequate" / "Excessive." Note pain if present.
Example client log:
- Ankle: limited bilaterally (3 inches knee-to-wall)
- Hip flexion: adequate
- Hip ER: limited L side (passive 30° vs 45° R)
- Thoracic ext: limited
- Shoulder flex: adequate
Translating findings to corrective work
Limited ankle → wall ankle mobs, weighted dorsiflexion, calf eccentrics. Limited hip flexion → 90/90 stretches, deep squat holds, hip CARs. Limited hip ER → 90/90 lift-offs, frog stretches, banded distractions. Limited thoracic ext → foam-roller extensions, prone Y/T/W raises, dead-hang positions. Limited shoulder flex → wall slides, prone Y raises, lat stretches.Don't stretch a client into pain or over-stretch a hypermobile client
Hypermobile clients (often female, sometimes with EDS or similar) need strength through ROM more than range gains. They already have range — they lack stability.
TL;DR
Flexibility = passive ROM. Mobility = controlled active ROM. Test 5 key joints (ankle, hip flexion, hip ER, thoracic, shoulder). Limited joints get mobility work; hypermobile joints get stability work.