Table 6.
Maximum moment arms, joint moments of force and MFL:TLC ratios for thoracic limb muscles
| Muscle–tendon unit | Joint of action | Joint angle of maximum moment arm (i.e. max flexion/extension) | Mean maximum muscle moment arm (mm) | Maximum joint moment of force (N.cm) | Muscle fascicle length: moment arm ratio |
|---|---|---|---|---|---|
| Triceps brachii | Shoulder | Max extension | 22.1 (17.7–31.1) | 777.9 | 1.0 |
| Elbow | All | 11.7 (5.2–14.0) | 411.8 | 2.0 | |
| Biceps brachii | Shoulder | Max extension | 6.1 (5.7–6.6) | 41.5 | 3.1 |
| Elbow | Max extension | 10.6 (7.6–13.6) | 72.1 | 1.8 | |
| Deltoid | Shoulder | Max extension | 4.7 (1.7–16.1) | 13.2 | 1.7 |
| Infraspinatus | Shoulder | Max extension | 2.5 (2.0–6.4) | 27.5 | 8.4 |
| Supraspinatus | Shoulder | Max flexion | 9.6 (7.1–11.7) | 103.7 | 3.6 |
| Latissimus dorsi | Shoulder | Max extension | 10.6 (2.4–18.7) | 29.7 | 13.1 |
| Teres major | Shoulder | Max extension | 5.2 (4.0–12.8) | 27.0 | 10.0 |
| Brachialis | Elbow | Max extension | 8.2 (7.0–9.6) | 10.7 | 3.7 |
| Extensors (combined) | Elbow | Max extension | 5.1 (3.5–5.9) | 30.6 | 2.2 |
| Flexors (combined) | Elbow | Max extension | 2.6 (1.1–4.0) | 59.0 | 5.0 |
| Extensor digitorum communis | Wrist | All | 2.5 (1.9–3.5) | 5.50 | 5.6 |
| Flexor digitorum profundus | Wrist | Max extension | 6.8 (5.2–7.6) | 74.8 | 1.6 |
| Flexor digitorum superficialis | Wrist | Max extension | 5.1 (3.8–5.7) | 50.0 | 1.2 |