📖 Static demo — read-only snapshot
You’re browsing a static build of the Body IQ knowledge graph, so everything loads with no backend. A few things that need the live server are turned off here:
- Global search (sidebar) is disabled — it queries the API.
- The JSON API and the API “Try it” playgroundaren’t included.
- The data is a snapshot — it refreshes only when the demo is rebuilt, not live from the database.
Everything else — the body map, progression ladders, coverage heatmap, exercise finder, and all anatomy/exercise/source pages — works fully. The full app (live search + API + database) runs from the source on GitHub.
Hand Assessment Reference
Normative pinch and grip values, intrinsic-muscle outcome measures, and quick-reference clinical tests for the hand.
Evidence-base caveats
- Isolated intrinsic-muscle training has sparse evidence; the only EMG-validated exercise is rubber-band finger abduction (Boudreau 2022).
- Grip/pinch dynamometry cannot isolate intrinsic function. The Rotterdam Intrinsic Hand Myometer (RIHM) is the validated alternative but is rarely available clinically (Schreuders 2006; McGee 2019).
- Normative values below are approximated from Mathiowetz 1985 (dominant hand). Newer data suggest lower absolute values in contemporary populations (Sayadizadeh 2025; Larson 2017; Werle 2009).
Grip strength (kg, dominant hand)
| Age band | Male | Female |
|---|---|---|
| 20–24 | 45–50 | 25–30 |
| 25–39 | 48–54 | 27–32 |
| 40–54 | 45–50 | 25–30 |
| 55–69 | 40–45 | 22–27 |
| 70+ | 30–35 | 18–22 |
Pinch strength (kg, dominant hand)
| Age band | Tip ♂ | Tip ♀ | Lateral ♂ | Lateral ♀ | 3-jaw ♂ | 3-jaw ♀ |
|---|---|---|---|---|---|---|
| 20–24 | 5.5–6.5 | 3.5–4.5 | 8.5–10.0 | 5.5–6.5 | 7.5–9.0 | 4.5–5.5 |
| 25–39 | 6.0–7.0 | 4.0–5.0 | 9.0–11.0 | 6.0–7.0 | 8.0–10.0 | 5.0–6.0 |
| 40–54 | 5.5–6.5 | 3.5–4.5 | 8.5–10.0 | 5.5–6.5 | 7.5–9.0 | 4.5–5.5 |
| 55–69 | 5.0–6.0 | 3.0–4.0 | 7.5–9.0 | 5.0–6.0 | 7.0–8.5 | 4.0–5.0 |
| 70+ | 4.5–5.5 | 2.5–3.5 | 6.5–8.0 | 4.5–5.5 | 6.0–7.5 | 3.5–4.5 |
Typical pinch-to-grip ratios: tip ≈ 15–20%; lateral ≈ 20–25%. Not validated as a measure of intrinsic function.
Intrinsic-specific outcome measures
Rotterdam Intrinsic Hand Myometer (RIHM)
Validated, reliable (ICC 0.85–0.95), and more sensitive than grip/pinch for detecting intrinsic weakness. Measures isolated index/small finger abduction, thumb opposition, and intrinsic-plus position. Normative adult data available (McGee 2019).
Key citations: Schreuders 2006; McGee 2019, 2024; Selles 2006 (CMT).
General hand-function measures (do not isolate intrinsics)
- DASH — Disabilities of the Arm, Shoulder and Hand
- AUSCAN — Australian/Canadian Hand Osteoarthritis Index
- Moberg pick-up test (dexterity + sensibility)
- Purdue Pegboard and 9-Hole Peg Test (dexterity)
Quick-reference clinical tests
Bunnell Intrinsic Tightness Test
Detect intrinsic shorteningPassively flex PIP with MCP extended, then with MCP flexed. Greater PIP flexion available with MCP flexed = intrinsic tightness.
Qualitative / diagnostic — not a reliability-established outcome measure.
Lumbrical-Plus Test
Paradoxical IP extension during attempted flexionPatient tries to make a fist; IP joints extend instead of flexing — suggests lumbrical dominance from a displaced FDP insertion (often post tendon injury).
Qualitative / diagnostic — not a reliability-established outcome measure.
Froment Sign
Adductor pollicis weakness (ulnar nerve)Patient holds paper between thumb and lateral index; thumb IP hyperflexes (FPL substitution) when the paper is pulled. Positive = adductor pollicis weakness.
Qualitative / diagnostic — not a reliability-established outcome measure.
Wartenberg Sign
Small-finger abductor (ADM) overpullAt rest, the small finger abducts and cannot be adducted — third palmar interosseous weakness (ulnar nerve).
Qualitative / diagnostic — not a reliability-established outcome measure.
Related
This page is a reference scaffold — pinch-grip calculators, age-adjusted percentile plots, and RIHM normative tables are planned. Contributions welcome.