Functional specialization and ontogenetic scaling of limb anatomy in Alligator mississippiensis
Journal of Anatomy (2010) 216, pp. 423–445
doi: 10.1111/j.1469-7580.2009.01202.x
The normalisation of average muscle architecture data for adult American alligators (Alligator mississippiensis of +10 Kg body mass) was performed using an incorrect divisor. Rather than normalisation of muscle architecture data using division by derivations of body mass (body mass0.67 for area measures such as muscle physiological cross-sectional area [PCSA], and body mass0.33 for linear measurements such as muscle fascicle lengths), data from an older dataset normalised using division by derivations of body volume were mistakenly included in the final manuscript.
In Table 2 (pp. 427–428) and Table 3 (pp. 429–450), the values quoted for the following data are one factor of ten too large: average normalised fascicle length (column 6, Lfasc/Mbody0.33 and column seven, its standard deviation), average normalised tendon length (column 12, Ltend/Mbody0.33 and column 13, its standard deviation). The values quoted for average normalised muscle PCSA (column 14, PCSA/Mbody0.67 and column 15, its standard deviation) are two factors of ten too large. Correspondingly, the values on the scale bar on the X-axis for Figures 1 and 2 (pp431) are two factors of ten too large, and the values on the scale bar on the Y-axis for Figures 1 and 2 are one factor of ten too large. Values quoted for average normalised fascicle length and PCSA in the following sections of text are also incorrect by one and two factors of ten, respectively.
Table 2.
Average muscle properties in the pectoral limb of adult (10 ± Kg) A. mississippiensis.
| Muscle | Abv. | Functional Group | Mmusc/Mbody | SD Mmusc/Mbody | Lfasc/Mbody0.33 | SD Lfasc/Mbody0.33 | θ (°) | SD θ (°) | Mtend/Mbody | SD Mtend/Mbody | Ltend/Mbody0.33 | SD Ltend/Mbody0.33 | PCSA/Mbody0.67 | SD PCSA/Mbody0.67 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Rhombodeus | RHO | Scapular Adductors | 0.02027% | 0.00742% | 0.548% | 0.114% | 3 | 7 | – | – | – | – | 0.00363% | 0.00158% |
| Serratus ventralis cervicus | SVC | Scapular Adductors | 0.04954% | 0.00701% | 1.226% | 0.127% | – | – | – | – | – | – | 0.00384% | 0.00062% |
| Serratus ventralis thoracis | SVT | Scapula Flexors | 0.13247% | 0.00811% | 1.673% | 0.351% | 4 | 9 | – | – | – | – | 0.00762% | 0.00142% |
| Latissimusdorsi | LD | Scapular Extensors | 0.08161% | 0.00407% | 2.104% | 0.205% | – | – | – | – | – | – | 0.00369% | 0.00038% |
| Levator scapulae | LS | Scapular Extensors | 0.17753% | 0.02144% | 2.560% | 0.312% | – | – | – | – | – | – | 0.00661% | 0.00109% |
| Trapezius | TRA | Scapular Extensors | 0.05444% | 0.01585% | 1.766% | 0.174% | – | – | – | – | – | – | 0.00293% | 0.00088% |
| Costocoracoideus profundus | COCP | Coracoidal Retractors | 0.01384% | 0.00468% | 0.839% | 0.231% | 2 | 6 | – | – | – | – | 0.00162% | 0.00073% |
| Costocoracoideus superficialis | COCS | Coracoidal Retractors | 0.07405% | 0.00973% | 1.888% | 0.253% | 1 | 3 | – | – | – | – | 0.00378% | 0.00088% |
| Deltoideus scapularis | DS | Shoulder Abductors | 0.03163% | 0.00248% | 0.653% | 0.178% | 26 | 4 | 0.00058% | 0.00016% | 0.620% | 0.148% | 0.00426% | 0.00079% |
| Scapulohumeralis caudalis | SHC | Shoulder Abductors | 0.02722% | 0.00541% | 1.102% | 0.223% | – | – | – | – | – | – | 0.00236% | 0.00046% |
| Teres major | TM | Shoulder Abductors | 0.02958% | 0.00168% | 1.452% | 0.291% | 14 | 21 | 0.00057% | 0.00012% | 0.508% | 0.164% | 0.00183% | 0.00048% |
| Pectoralis | PEC | Shoulder Flexors/Adductors | 0.69038% | 0.03229% | 4.288% | 0.528% | – | – | – | – | – | – | 0.01538% | 0.00199% |
| Corachobrachialis brevis ventralis | CBV | Shoulder Flexors/Adductors | 0.05209% | 0.00734% | 1.532% | 0.245% | – | – | – | – | – | – | 0.00328% | 0.00079% |
| Subscapularis | SS | Shoulder Flexors/Adductors | 0.08206% | 0.04538% | 1.214% | 0.315% | 12 | 18 | – | – | – | – | 0.00616% | 0.00350% |
| Corachobrachialis brevis dorsalis | CBD | Shoulder Extensors | 0.01187% | 0.00942% | 0.888% | 0.209% | – | – | – | – | – | – | 0.00119% | 0.00067% |
| Deltoideus clavicularis | DC | Shoulder Extensors | 0.08466% | 0.01145% | 1.981% | 0.326% | – | – | – | – | – | – | 0.00414% | 0.00091% |
| Supracoracoideus | SC | Shoulder Extensors | 0.09382% | 0.01445% | 1.706% | 0.140% | – | – | – | – | – | – | 0.00520% | 0.00072% |
| Abductor radialis | AB-R | Elbow Flexors | 0.00952% | 0.00076% | 0.402% | 0.060% | 26 | 2 | 0.000029% | 0.000000% | 0.311% | 0.000% | 0.00204% | 0.00031% |
| Biceps brachii | BB | Elbow Flexors | 0.04945% | 0.00377% | 1.831% | 0.389% | 9 | 11 | 0.00109% | 0.00018% | 1.176% | 0.112% | 0.00253% | 0.00033% |
| Brachialis | BR | Elbow Flexors | 0.02071% | 0.00226% | 1.715% | 0.287% | – | – | – | – | – | – | 0.00117% | 0.00024% |
| Flexor ulnaris | FUL | Elbow Flexors | 0.01511% | 0.00359% | 0.430% | 0.149% | 23 | 3 | 0.00032% | 0.00020% | 0.398% | 0.223% | 0.00328% | 0.00102% |
| Humeroradialis | HR | Elbow Flexors | 0.03251% | 0.00859% | 1.857% | 0.146% | – | – | 0.00068% | 0.00054% | 0.589% | 0.224% | 0.00166% | 0.00046% |
| Triceps longus lateralus | TLL | Shoulder Flexors/Elbow Extensors | 0.09019% | 0.01047% | 1.176% | 0.124% | 24 | 5 | 0.00120% | 0.00060% | 0.808% | 0.412% | 0.00669% | 0.00124% |
| Triceps longus medialis | TLM | Shoulder Flexors/Elbow Extensors | 0.08103% | 0.01296% | 1.048% | 0.179% | 24 | 4 | 0.00289% | 0.00180% | 2.073% | 1.124% | 0.00680% | 0.00139% |
| Triceps brevis caudalis | TBCD | Elbow Extensors | 0.05299% | 0.00936% | 0.947% | 0.149% | 25 | 2 | 0.00103% | 0.00055% | 0.738% | 0.357% | 0.00486% | 0.00098% |
| Triceps brevis cranialis | TBCR | Elbow Extensors | 0.07647% | 0.01448% | 0.910% | 0.260% | 30 | 5 | 0.00623% | 0.00666% | 0.940% | 0.270% | 0.00707% | 0.00153% |
| Triceps brevis intermedius | TBI | Elbow Extensors | 0.08004% | 0.01810% | 0.908% | 0.091% | 26 | 6 | 0.00624% | 0.00357% | 0.660% | 0.251% | 0.00740% | 0.00126% |
| Pronator quadratus | PQ | Elbow Pronators | 0.03271% | 0.00395% | 0.454% | 0.090% | 30 | 3 | – | – | – | – | 0.00600% | 0.00098% |
| Pronator teres | PT | Elbow Pronators | 0.04340% | 0.00365% | 0.600% | 0.057% | 27 | 5 | 0.00025% | 0.00000% | 0.181% | 0.000% | 0.00608% | 0.00074% |
| Supinator | SUP | Elbow Supinators | 0.02392% | 0.00256% | 1.066% | 0.175% | 25 | 2 | 0.00137% | 0.00000% | 0.958% | 0.000% | 0.00199% | 0.00055% |
| Extensor carpi radialis brevis | ECR-B | Wrist Dorsiflexors | 0.01227% | 0.00191% | 0.604% | 0.088% | 20 | 11 | 0.00038% | 0.00012% | 0.574% | 0.470% | 0.00178% | 0.00030% |
| Extensor carpi radialis longus | ECR-L | Wrist Dorsiflexors | 0.01205% | 0.00240% | 0.580% | 0.067% | 20 | 2 | 0.00063% | 0.00032% | 0.849% | 0.344% | 0.00187% | 0.00046% |
| Extensor carpi ulnaris longus | ECU-L | Wrist Dorsiflexors | 0.01082% | 0.00145% | 0.834% | 0.139% | 15 | 8 | 0.00067% | 0.00018% | 1.551% | 0.117% | 0.00120% | 0.00026% |
| Flexor carpi ulnaris | FCU | Wrist Plantarflexors | 0.03537% | 0.00432% | 0.379% | 0.081% | 29 | 4 | 0.00083% | 0.00054% | 0.607% | 0.450% | 0.00799% | 0.00176% |
| Flexor digitorum longus 1 (fore) | FDL1 | Wrist Plantarflexors | 0.00876% | 0.00131% | 0.794% | 0.210% | 22 | 3 | 0.00139% | 0.00185% | – | – | 0.00102% | 0.00028% |
| Flexor digitorum longus 2 (fore) | FDL2 | Wrist Plantarflexors | 0.02517% | 0.00520% | 0.426% | 0.075% | 25 | 3 | 0.00407% | 0.00183% | 1.559% | 0.380% | 0.00505% | 0.00050% |
| Extensor digitorum superficialis | EDS | Digital Dorsiflexors | 0.01561% | 0.00257% | 0.428% | 0.129% | 22 | 12 | 0.00007% | 0.00000% | – | – | 0.00328% | 0.00087% |
| Flexor digitorum brevis (fore) | FDBF | Digital Plantarflexors | 0.04061% | 0.03293% | 0.345% | 0.064% | 29 | 15 | 1.50E-05 | 6.81E-06 | 0.745% | 0.451% | 0.00890% | 0.00761% |
Table 3.
Average muscle properties in the pelvic limb of adult (10 ± Kg) A. mississippiensis
| Muscle | Abv. | Functional Group | Mmusc/Mbody | SD Mmusc/Mbody | Lfasc/Mbody0.33 | SD Lfasc/Mbody0.33 | θ (°) | SD θ (°) | Mtend/Mbody | SD Mtend/Mbody | Ltend/Mbody0.33 | SD Ltend/Mbody0.33 | PCSA/Mbody0.67 | SD PCSA/Mbody0.67 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Caudofemoralis brevis | CFB | Hip Extensors/Knee Flexors | 0.13636% | 0.01831% | 2.618% | 0.211% | 4 | 6 | – | – | 0.866% | 0.000% | 0.00487% | 0.00042% |
| Caudofemoralis longus | CFL | Hip Extensors/Knee Flexors | 1.39420% | 0.69839% | 6.594% | 0.700% | 20 | 23 | 0.00743% | 0.00126% | 2.678% | 0.797% | 0.01735% | 0.00955% |
| Flexor tibialis externus | FTE | Hip Extensors/Knee Flexors | 0.52868% | 0.78821% | 3.841% | 0.266% | 8 | 19 | 0.00563% | 0.00268% | 3.082% | 1.322% | 0.01272% | 0.01953% |
| Flexor tibialis internus 1 | FTI1 | Hip Extensors/Knee Flexors | 0.02355% | 0.00409% | 3.561% | 0.314% | – | – | 0.00007% | 0.00001% | 0.262% | 0.042% | 0.00063% | 0.00013% |
| Flextor tibialis internus 2 | FTI2 | Hip Extensors/Knee Flexors | 0.13574% | 0.00447% | 4.463% | 1.182% | 2 | 5 | 0.00090% | 0.00029% | 0.505% | 0.218% | 0.00311% | 0.00119% |
| Flexor tibialis internus 3 | FTI3 | Hip Extensors/Knee Flexors | 0.06933% | 0.00393% | 1.993% | 0.178% | 13 | 11 | 0.00043% | 0.00030% | 0.526% | 0.439% | 0.00318% | 0.00041% |
| Flexor tibialis internus 4 | FTI4 | Hip Extensors/Knee Flexors | 0.03439% | 0.00358% | 3.242% | 0.456% | – | – | 0.00084% | 0.00031% | 1.020% | 0.459% | 0.00102% | 0.00019% |
| Iliofibularis | ILFB | Hip Extensors/Knee Flexors | 0.05515% | 0.00640% | 3.552% | 0.534% | – | – | 0.00068% | 0.00032% | 1.044% | 0.157% | 0.00151% | 0.00038% |
| Ischiotrochantericus | ISTR | Hip Extensors/Knee Flexors | 0.03338% | 0.01589% | 0.795% | 0.095% | 33 | 8 | 0.00201% | 0.00148% | 0.651% | 0.313% | 0.00329% | 0.00153% |
| Pubo-ischio-tibialis | PIT | Hip Extensors/Knee Flexors | 0.05114% | 0.02539% | 3.694% | 0.582% | 5 | 7 | 0.00049% | 0.00031% | 0.357% | 0.174% | 0.00138% | 0.00074% |
| Pubo-ischio-femoralis externus 1 | PIFE1 | Hip Flexors | 0.11409% | 0.01461% | 2.935% | 0.794% | 5 | 11 | 0.00084% | 0.00039% | 0.668% | 0.303% | 0.00383% | 0.00116% |
| Pubo-ischio-femoralis internus 1 | PIFI1 | Hip Flexors | 0.11971% | 0.00923% | 2.519% | 0.504% | – | – | – | – | – | – | 0.00466% | 0.00107% |
| Pubo-ischio-femoralis internus 2 | PIFI2 | Hip Flexors | 0.49982% | 0.06341% | 3.901% | 0.343% | – | – | 0.00308% | 0.00091% | 1.214% | 0.514% | 0.01218% | 0.00201% |
| Iliofemoralis | IF | Hip Abductors | 0.09494% | 0.00629% | 1.634% | 0.219% | 15 | 15 | - | – | – | – | 0.00518% | 0.00059% |
| Adductor 1 | ADD1 | Hip Adductors | 0.09812% | 0.01788% | 3.657% | 0.437% | – | – | - | – | – | – | 0.00261% | 0.00077% |
| Adductor 2 | ADD2 | Hip Adductors | 0.04565% | 0.00498% | 4.034% | 0.507% | – | – | 0.00222% | 0.00000% | 0.194% | 0.000% | 0.00108% | 0.00018% |
| Pubo-ischio-femoralis externus 2 | PIFE2 | Hip Adductors | 0.11381% | 0.01523% | 1.808% | 0.315% | 24 | 15 | 0.00048% | 0.00018% | 0.405% | 0.207% | 0.00537% | 0.00107% |
| Pubo-ischio-femoralis externus 3 | PIFE3 | Hip Adductors | 0.08071% | 0.01316% | 1.346% | 0.109% | 21 | 12 | 0.00054% | 0.00054% | 0.363% | 0.147% | 0.00520% | 0.00097% |
| Ambiens 1 | AMB1 | Knee Extensors | 0.09250% | 0.00523% | 1.915% | 0.263% | 8 | 11 | 0.00284% | 0.00038% | 2.554% | 0.899% | 0.00449% | 0.00054% |
| Ambiens 2 | AMB2 | Knee Extensors | 0.01504% | 0.00570% | 1.446% | 0.629% | 9 | 11 | 0.00049% | 0.00028% | 0.591% | 0.671% | 0.00110% | 0.00063% |
| Femorotibialis externus | FMTE | Knee Extensors | 0.05950% | 0.00633% | 0.874% | 0.064% | 30 | 2 | 0.00094% | 0.00042% | 0.564% | 0.248% | 0.00561% | 0.00086% |
| Femorotibialis internus | FMTI | Knee Extensors | 0.19254% | 0.01701% | 1.092% | 0.121% | 33 | 5 | 0.01007% | 0.00344% | 0.758% | 0.257% | 0.01401% | 0.00146% |
| Iliotibialis 1 | IT1 | Knee Extensors | 0.02839% | 0.00269% | 2.293% | 0.248% | – | – | – | – | – | – | 0.00119% | 0.00025% |
| Iliotibialis 2 | IT2 | Knee Extensors | 0.18669% | 0.00815% | 1.536% | 0.215% | 30 | 4 | 0.00323% | 0.00115% | 1.796% | 0.742% | 0.01005% | 0.00138% |
| Iliotibialis 3 | IT3 | Knee Extensors | 0.05251% | 0.00640% | 1.600% | 0.681% | 22 | 2 | 0.00148% | 0.00038% | 1.821% | 1.668% | 0.00321% | 0.00112% |
| Extensor digitorum longus | EDL | Ankle Dorsiflexors | 0.07436% | 0.00801% | 1.786% | 0.464% | 20 | 10 | 0.00095% | 0.00026% | 1.009% | 0.125% | 0.00385% | 0.00100% |
| Tibialis anterior | TA | Ankle Dorsiflexors | 0.04777% | 0.00600% | 2.809% | 0.232% | - | - | 0.00049% | 0.00009% | 0.474% | 0.077% | 0.00161% | 0.00019% |
| Fibularis brevis | FB | Ankle Plantarflexors | 0.01385% | 0.00132% | 0.607% | 0.115% | 25 | 6 | 0.00037% | 0.00022% | 0.273% | 0.105% | 0.00200% | 0.00040% |
| Flexor digitorum longus (hind) | FDLH | Ankle Plantarflexors | 0.03203% | 0.02360% | 0.661% | 0.219% | 26 | 4 | 0.00440% | 0.00392% | 2.177% | 1.176% | 0.00434% | 0.00261% |
| Flexor hallucus longus | FHL | Ankle Plantarflexors | 0.01924% | 0.00258% | 0.729% | 0.157% | 23 | 1 | 0.00318% | 0.00196% | 1.841% | 0.519% | 0.00234% | 0.00030% |
| Fibularis longus | FL | Ankle Plantarflexors | 0.03196% | 0.00336% | 0.676% | 0.172% | 28 | 2 | 0.00086% | 0.00044% | 0.424% | 0.207% | 0.00416% | 0.00115% |
| Gastrocnemius externus | GE | Ankle Plantarflexors | 0.15581% | 0.02036% | 0.998% | 0.169% | 29 | 6 | 0.01249% | 0.01600% | 1.729% | 1.481% | 0.01301% | 0.00184% |
| Gastrocnemius internus | GI | Ankle Plantarflexors | 0.06311% | 0.00599% | 2.673% | 0.207% | 9 | 10 | 0.00135% | 0.00115% | 0.659% | 0.337% | 0.00218% | 0.00025% |
| Interossessus cruri | IC | Ankle Plantarflexors | 0.05599% | 0.00395% | 0.683% | 0.224% | 29 | 10 | 0.00254% | 0.00067% | 1.366% | 0.343% | 0.00709% | 0.00166% |
| Pronator profundus | PP | Ankle Plantarflexors | 0.01216% | 0.00263% | 0.552% | 0.081% | 23 | 14 | – | – | – | – | 0.00189% | 0.00027% |
| Extensor digitorum brevis | EDB | Digital Dorsiflexors | 0.03273% | 0.01220% | 0.635% | 0.135% | 29 | 11 | 0.00212% | 0.00239% | 0.722% | 0.516% | 0.00445% | 0.00218% |
| Extensor hallucis brevis | EHB | Digital Dorsiflexors | 0.01326% | 0.00163% | 0.639% | 0.121% | 16 | 13 | 0.00048% | 0.00023% | 0.550% | 0.292% | 0.00177% | 0.00029% |
| Extensor hallucis longus | EHL | Digital Dorsiflexors | 0.00922% | 0.00163% | 0.842% | 0.144% | 36 | 11 | 0.00038% | 0.00030% | 0.321% | 0.061% | 0.00098% | 0.00015% |
| Flexor digitorum brevis (hind) | FDBH | Digital Plantarflexors | 0.01799% | 0.00113% | 0.347% | 0.047% | 27 | 6 | 0.00182% | 0.00111% | 0.503% | 0.341% | 0.00436% | 0.00085% |
| Flexor hallucus brevis | FHB | Digital Plantarflexors | 0.04061% | 0.03293% | 0.345% | 0.064% | 24 | 13 | 0.00150% | 0.00068% | 0.745% | 0.451% | 0.00890% | 0.00761% |
Results: Mean distribution of fascicle length, pennation angle and PCSA (pp. 432, column 1) and;
Results: Mean distribution of external tendons, lengths and masses (pp. 432, columns 1–2).
Corrected Figure 1 and Tables 2 and 3 is now provided below.
The results of the scaling analysis (which used un-normalised, raw data), and all qualitative conclusions on the functional specialisation of limb musculature in A. mississippiensis are unaffected by this error.
The authors would like to apologise for this oversight.
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