Table 2.
Muscle-specific physiology parameters taken from architectural and electrophysiological measurements as described in the Methods. Muscle masses are normalized to a rat body mass of 300 g. Architectural values were used in the musculoskeletal model. Unless otherwise indicated, architectural measurements including mass, optimal fiber length, maximum isometric tension and maximum shortening velocity were taken from n=4 rats, while electrophysiological measurements of maximum isometric tension and shortening velocity, and tendon slack lengths were taken from n=2 rats.
| Abbreviation | Muscle Name | Mass (mg) | l0 (mm) | θ0 (deg) | P0 (g) Architecture | P0 (g) Physiology | vmax (mm s−1)Architecture | vmax (mm s−1) Physiology | lts (mm) | |
|---|---|---|---|---|---|---|---|---|---|---|
| AB | adductor brevis | 1087 ±157 | 22.8 ±0.4 | 12 ± 5 | 1246 ±80 | 406 ± 21 | 0±0 | |||
| AL | adductor longus | 94 ± 19 | 16.6 ±2.1 | 9± 4 | 106 ± 15 | 93 ± 17 | 4.5 ± 0.3 | |||
| AM | adductor magnus | 280 ±93 | 28.4 ±1.0 | 0± 0 | 308 ± 24 | 506 ± 32 | 0±0 | |||
| BFa | biceps femoris anterior | 470 ± 99 | 39.7 ± 3.9 | 0± 1 | 346 ± 23 | 706 ± 60 | 0±0 | |||
| BFp | biceps femoris posterior | 1655 ± 348 | 37.6 ± 1.7 | 7± 5 | 1274 ± 83 | 669 ± 71 | 0±0 | |||
| CF | caudofemoralis | 275 ± 91 | 37.9 ± 3.2 | 0± 0 | 210 ± 25 | 675 ± 77 | 0±0 | |||
| EDL | extensor digitorum longus | 146 ± 14 | 13.7 ±1.0 | 10 ± 3 | 225 ± 8 | 265 ± 65 | 243 ± 15 | 205 ± 13 | 9.0 ± 0.4 | |
| EHL | extensor hallucis longus | 13±2 | 12.1 ±0.8 | 5± 3 | 25 ± 2 | 216 ± 22 | 13.6±1.2 | |||
| FDL | flexor digitorum longus | 470 ± 53 | 9.0 ± 0.5 | 11 ± 5 | 1124 ±217 | 1344 ± 494 | 160 ± 33 | 140 ± 17 | 8.7 ± 0.8 | |
| FHL | flexor hallucis longus | 22 ± 1 | 10.8 ±1.0** | 2± 4** | 45 ± 1** | 193 ± 6** | 9.7 ± 0.0 | |||
| GI | gemellus inferior | 55 ± 2 | 4.2 ± 0.2 | 18 ± 7 | 291 ± 38 | 74 ± 9 | 0±0 | |||
| GS | gemellus superior | 12 ±2 | 6.1 ± 1.1 | 10 ± 14 | 38 ± 13 | 109 ± 31 | 0±0 | |||
| GMa | gluteus maximus | 793 ± 33 | 19.6 ±4.7 | 12 ± 10 | 942 ± 276 | 349 ± 75 | 4.8 ± 0.4 | |||
| GMe | gluteus medius | 1444 ± 182 | 19.9 ±2.7 | 12 ± 2 | 1912 ± 233 | 355 ± 35 | 0±0 | |||
| GMi | gluteus minimus | 378 ± 25 | 11.8 ±0.3 | 16 ± 9 | 754 ± 61 | 211 ± 22 | 0±0 | |||
| GA | gracillis anterior | 168 ± 32 | 30.3 ± 4.9 | 0± 0 | 158 ± 10 | 539 ± 50 | 0±0 | |||
| GP | gracillis posterior | 246 ± 43 | 29.3 ± 4.1 | 3± 4 | 240 ± 35 | 163 ± 27 | 0.9 ± 0.1 | |||
| IP | iliacus | 999 ± 77 | 22.3 ± 0.9* | 7± 4* | 1043 ± 84* | 402 ± 50* | ||||
| psoas major | 1179 ± 126 | 23.8 ± 3.3* | 15 ± 3* | 1151 ±157* | 418 ± 64* | 4.1 ± 0.0 | ||||
| LG | lateral gastrocnemius | 805 ± 161 | 12.5 ±0.8 | 9± 6 | 1863 ± 116 | 1734 ± 43 | 223 ± 17 | 209 ± 17 | 9.4 ± 0.3 | |
| MG | medial gastrocnemius | 720 ± 56 | 14.6 ± 0.4 | 13 ± 4 | 1188±92 | 1364 ± 30 | 260 ± 25 | 238 ± 6 | 9.1 ±0.3 | |
| OE | obturator externus | 194 ± 13 | 6.0 ± 0.8 | 16 ± 6 | 732 ±80 | 106 ± 10 | 0±0 | |||
| OI | obturator internus | 54 ± 11 | 4.5 ± 0.7 | 7± 6 | 307 ± 35 | 81 ± 10 | 2.8 ± 4.0 | |||
| Pec | pectineus | 233 ± 17 | 10.9 ±0.7* | 7± 1* | 503 ± 14* | 193 ± 2* | 0±0 | |||
| Per | PerB | peroneus brevis | 88 ± 11 | 8.6 ± 0.9 | 6± 7 | 243 ± 20 | 501 ± 40 | 152 ± 16 | 117±4 | 10.3 ± 0.2 |
| PerL | peroneus longus | 131 ± 16 | 7.6 ± 0.3 | 9± 2 | 404 ± 32 | 622 ± 122 | 135 ± 12 | 113±7 | 12.7 ±0.1 | |
| PerQa | peroneus digiti quarti | 31 ± 4 | 8.8 ± 1.9 | 7± 5 | 86 ± 15 | 139 ± 2 | 157 ± 36 | 116±19 | 9.1 ± 1.4 | |
| PerQi | peroneus digiti quinti | 21 ± 3 | 8.6 ± 0.8* | 4± 1* | 56 ± 3* | 113 ± 22 | 152 ± 13* | 116±4 | 19.6 ± 0.9 | |
| Pir | piriformis | 478 ± 60 | 10.8±1.6 | 16 ± 8 | 1137±123 | 193 ± 19 | 0±0 | |||
| Pla | plantaris | 308 ± 27 | 12.5±1.5 | 11 ± 4 | 572 ± 56 | 792 ± 13 | 223 ± 17 | 207 ± 13 | 6.7 ± 0.2 | |
| Pop | popliteus | 90 ± 5 | 6.5 ± 0.6 | 13 ± 6 | 298 ± 17 | 115±5 | 0±0 | |||
| QF | quadratus femoris | 155 ± 14 | 11.0±1.0 | 3± 2 | 306 ± 18 | 197 ± 15 | 0±0 | |||
| SM | semimembranosus | 1291 ± 320 | 35.7 ± 1.0 | 0± 0 | 1043 ± 69 | 634 ± 57 | 0±0 | |||
| ST | STa | semitendinosus accessory | 177 ± 25 | 34.1 ± 6.4 | 0± 0 | 142 ± 23 | 607 ± 95 | 0±0 | ||
| STp | semitendinosus principal | 707 ± 101 | 43.6 ± 10.4 | 0± 0 | 463 ± 148 | 775 ± 193 | 0±0 | |||
| Sol | soleus | 155 ± 27 | 16.0 ±5.1 | 4± 9 | 145 ± 27 | 234 ± 29 | 89 ± 22 | 93 ± 11 | 9.5 ± 0.5 | |
| TFL | tensor fascia latae | 362 ± 15 | 20.6 ± 0.6* | 11 ± 8* | 397 ± 30* | 367 ± 27* | 0±0 | |||
| TA | tibialis anterior | 542 ± 60 | 15.2 ±0.7 | 9± 4 | 878 ± 81 | 1004 ± 45 | 271 ± 29 | 290 ± 6 | 11.9±1.5 | |
| TP | tibialis posterior | 85 ± 5 | 5.4 ± 1.4 | 5± 3 | 361 ± 83 | 605 ± 51 | 97 ± 31 | 68 ± 1 | 12.4 ±0.2 | |
| RF | rectus femoris | 900 ± 67 | 12.2 ±0.9 | 11 ± 5 | 1681 ± 86 | 1859 ± 71 | 216 ± 19 | 227 ± 13 | 6.6 ± 0.8 | |
| VI | vastus intermedius | 181 ± 12 | 11.6 ±0.6 | 14 ± 3 | 260 ± 25 | 65 ± 9 | 6.6 ± 0.8 | |||
| VL | vastus lateralis | 1113 ± 170 | 19.8 ± 0.3 | 14 ± 3 | 1517 ± 79 | 352 ± 25 | 6.6 ± 0.8 | |||
| VM | vastus medialis | 396 ± 26 | 15.6±1.3 | 11 ± 6 | 620 ± 73 | 611 ± 87 | 278 ± 34 | 161 ± 3 | 6.6 ± 0.8 | |
*
n=3
**
n=2.