Table 2.
Excursion (mm), sarcomere length (Ls), relative tension and muscle force estimates as a function of joint angle in the (A) anterior superficial masseter, (B) deep masseter and (C) posterior superficial masseter of Callithrix jacchus and Saguinus oedipus. The bottom panel provides P-values for two-way (species × joint angle) repeated-measures ANOVAs comparing C. jacchus and S. oedipus
| Joint angle | Excursion (mm)*, † | Relative tension | |||||
| Ls | Active (%) | Passive (%) | Total (%) | Muscle force (N) | |||
| (A) Anterior superficial masseter | |||||||
| C. jacchus | 0 | 0 | 1.63 | 53.72 | 0 | 53.72 | 3.99 |
| 5 | 0.91±0.05 | 1.78±0.00 | 73.21±0.17 | 0 | 73.21±0.17 | 5.44±0.01 | |
| 10 | 1.77±0.09 | 1.93±0.00 | 81.81±0.28 | 0 | 81.81±0.28 | 6.07±0.02 | |
| 15 | 2.58±0.12 | 2.07±0.01 | 89.92±0.36 | 0 | 89.92±0.36 | 6.68±0.03 | |
| 20 | 3.34±0.15 | 2.20±0.01 | 97.54±0.46 | 0 | 97.54±0.46 | 7.24±0.03 | |
| 25 | 4.05±0.18 | 2.32±0.01 | 100.00±0.00 | 0 | 100.00±0.00 | 7.43±0.00 | |
| 30 | 4.71±0.21 | 2.43±0.02 | 100.00±0.00 | 0.13±0.00 | 100.13±0.00 | 7.43±0.00 | |
| 35 | 5.32±0.23 | 2.54±0.02 | 99.94±0.06 | 0.15±0.01 | 100.09±0.05 | 7.43±0.00 | |
| 40 | 5.88±0.26 | 2.63±0.03 | 96.58±2.11 | 0.20±0.02 | 96.76±2.09 | 7.19±0.15 | |
| 45 | 6.40±0.29 | 2.72±0.04 | 90.82±2.80 | 0.31±0.08 | 91.13±2.72 | 6.77±0.20 | |
| 50 | 6.86±0.33 | 2.80±0.05 | 85.61±3.60 | 0.58±0.27 | 86.19±3.34 | 6.40±0.25 | |
| 55 | 7.28±0.37 | 2.87±0.07 | 80.96±4.51 | 0.95±0.45 | 81.91±4.07 | 6.08±0.30 | |
| S. oedipus | 0 | 0 | 1.51 | 34.19 | 0 | 34.19 | 3.00 |
| 5 | 1.10±0.05 | 1.71±0.01 | 66.07±1.84 | 0 | 66.07±1.84 | 5.80±0.16 | |
| 10 | 2.16±0.09 | 1.90±0.02 | 79.81±1.25 | 0 | 79.81±1.25 | 7.00±0.11 | |
| 15 | 3.21±0.12 | 2.08±0.03 | 90.75±1.77 | 0 | 90.75±1.77 | 7.96±0.16 | |
| 20 | 4.22±0.15 | 2.26±0.04 | 98.99±1.01 | 0 | 98.99±1.01 | 8.69±0.09 | |
| 25 | 5.20±0.18 | 2.44±0.04 | 100.00±0.00 | 0.09±0.05 | 100.09±0.05 | 8.78±0.00 | |
| 30 | 6.16±0.21 | 2.61±0.05 | 96.51±1.81 | 0.19±0.02 | 96.70±1.79 | 8.49±0.16 | |
| 35 | 7.09±0.23 | 2.78±0.05 | 87.03±3.52 | 0.48±0.14 | 87.51±3.38 | 7.68±0.30 | |
| 40 | 7.99±0.26 | 2.94±0.06 | 76.42±3.72 | 1.38±0.41 | 77.81±3.32 | 6.83±0.29 | |
| 45 | 8.87±0.29 | 3.09±0.06 | 66.14±3.87 | 2.88±0.66 | 69.02±3.22 | 6.06±0.28 | |
| 50 | 9.72±0.33 | 3.25±0.06 | 56.18±3.97 | 5.75±1.48 | 61.93±2.52 | 5.43±0.22 | |
| 55 | 10.54±0.37 | 3.39±0.06 | 46.55±4.03 | 12.05±3.58 | 58.60±0.77 | 5.14±0.07 | |
| ANOVA (P-values) | 0 | NA | NA | NA | NA | NA | NA |
| 5 | 0.045 | 0.002 | 0.018 | NA | 0.018 | 0.089 | |
| 10 | 0.031 | 0.193 | 0.193 | NA | 0.193 | 0.001 | |
| 15 | 0.022 | 0.671 | 0.671 | NA | 0.671 | 0.001 | |
| 20 | 0.015 | 0.163 | 0.259 | NA | 0.259 | <0.001 | |
| 25 | 0.011 | 0.057 | NS | 0.116 | 0.116 | <0.001 | |
| 30 | 0.008 | 0.026 | 0.127 | 0.055 | 0.128 | 0.003 | |
| 35 | 0.006 | 0.014 | 0.021 | 0.084 | 0.020 | 0.451 | |
| 40 | 0.005 | 0.009 | 0.009 | 0.044 | 0.008 | 0.338 | |
| 45 | 0.004 | 0.007 | 0.007 | 0.018 | 0.006 | 0.111 | |
| 50 | 0.004 | 0.005 | 0.005 | 0.026 | 0.004 | 0.044 | |
| 55 | 0.004 | 0.005 | 0.005 | 0.037 | 0.005 | 0.039 | |
| (B) Deep masseter | |||||||
| C. jacchus | 0 | 0 | 1.63 | 53.72 | 0 | 53.72 | 4.11 |
| 5 | 0.43±0.06 | 1.70±0.01 | 65.74±2.30 | 0 | 65.74±2.30 | 5.03±0.02 | |
| 10 | 0.84±0.11 | 1.77±0.03 | 72.09±2.00 | 0 | 72.09±2.00 | 5.52±0.04 | |
| 15 | 1.20±0.17 | 1.83±0.04 | 76.17±2.33 | 0 | 76.17±2.33 | 5.83±0.02 | |
| 20 | 1.54±0.21 | 1.89±0.05 | 79.53±3.01 | 0 | 79.53±3.01 | 6.08±0.03 | |
| 25 | 1.84±0.26 | 1.94±0.06 | 82.57±3.65 | 0 | 82.57±3.65 | 6.32±0.05 | |
| 30 | 2.11±0.30 | 1.99±0.07 | 85.28±4.25 | 0 | 85.28±4.25 | 6.52±0.06 | |
| 35 | 2.35±0.34 | 2.03±0.08 | 87.66±4.81 | 0 | 87.66±4.81 | 6.71±0.07 | |
| 40 | 2.56±0.38 | 2.07±0.09 | 89.72±5.35 | 0 | 89.72±5.35 | 6.86±0.09 | |
| 45 | 2.73±0.42 | 2.09±0.10 | 91.45±5.88 | 0 | 91.45±5.88 | 7.00±0.11 | |
| 50 | 2.87±0.46 | 2.12±0.11 | 92.55±6.20 | 0 | 92.55±6.20 | 7.08±0.07 | |
| 55 | 2.98±0.50 | 2.14±0.12 | 92.85±6.21 | 0 | 92.85±6.21 | 7.10±0.00 | |
| S. oedipus | 0 | 0 | 1.51 | 34.19 | 0 | 34.19 | 3.54 |
| 5 | 0.48±0.01 | 1.60±0.00 | 48.04±0.18 | 0 | 48.04±0.18 | 4.97±0.02 | |
| 10 | 0.94±0.01 | 1.68±0.00 | 61.43±0.39 | 0 | 61.43±0.39 | 6.36±0.04 | |
| 15 | 1.38±0.02 | 1.76±0.00 | 71.58±0.23 | 0 | 71.58±0.23 | 7.41±0.02 | |
| 20 | 1.81±0.03 | 1.83±0.00 | 76.10±0.33 | 0 | 76.10±0.33 | 7.88±0.03 | |
| 25 | 2.22±0.04 | 1.91±0.01 | 80.45±0.44 | 0 | 80.45±0.44 | 8.33±0.05 | |
| (B) Deep masseter | |||||||
| S. oedipus | 30 | 2.62±0.05 | 1.98±0.01 | 84.63±0.57 | 0 | 84.63±0.57 | 8.76±0.06 |
| 35 | 3.01±0.07 | 2.05±0.01 | 88.65±0.71 | 0 | 88.65±0.71 | 9.18±0.07 | |
| 40 | 3.37±0.08 | 2.11±0.01 | 92.51±0.87 | 0 | 92.51±0.87 | 9.58±0.09 | |
| 45 | 3.72±0.10 | 2.18±0.02 | 96.21±1.04 | 0 | 96.21±1.04 | 9.96±0.11 | |
| 50 | 4.06±0.12 | 2.24±0.02 | 99.07±0.67 | 0 | 99.07±0.67 | 10.25±0.07 | |
| 55 | 4.38±0.14 | 2.29±0.02 | 100.00±0.00 | 0 | 100.00±0.00 | 10.35±0.00 | |
| ANOVA (P-values) | 0 | NA | NA | NA | NA | NA | NA |
| 5 | 0.636 | 0.002 | 0.002 | NA | 0.002 | 0.761 | |
| 10 | 0.560 | 0.026 | 0.006 | NA | 0.006 | 0.006 | |
| 15 | 0.487 | 0.122 | 0.122 | NA | 0.122 | 0.001 | |
| 20 | 0.418 | 0.320 | 0.320 | NA | 0.320 | 0.002 | |
| 25 | 0.355 | 0.594 | 0.594 | NA | 0.594 | 0.002 | |
| 30 | 0.298 | 0.887 | 0.887 | NA | 0.887 | 0.002 | |
| 35 | 0.248 | 0.849 | 0.849 | NA | 0.849 | 0.003 | |
| 40 | 0.205 | 0.634 | 0.634 | NA | 0.634 | 0.003 | |
| 45 | 0.169 | 0.470 | 0.470 | NA | 0.470 | 0.003 | |
| 50 | 0.140 | 0.349 | 0.355 | NA | 0.355 | 0.003 | |
| 55 | 0.115 | 0.262 | 0.313 | NA | 0.313 | 0.002 | |
| (C) Posterior superficial masseter | |||||||
| C. jacchus | 0 | 0 | 1.63 | 53.72 | 0 | 53.72 | 4.23 |
| 5 | 0.12±0.07 | 1.65±0.01 | 57.02±2.06 | 0 | 57.02±2.06 | 4.49±0.16 | |
| 10 | 0.22±0.14 | 1.67±0.02 | 59.94±3.89 | 0 | 59.94±3.89 | 4.72±0.31 | |
| 15 | 0.32±0.20 | 1.68±0.03 | 61.95±4.98 | 0 | 61.95±4.98 | 4.88±0.39 | |
| 20 | 0.40±0.25 | 1.70±0.04 | 63.13±5.46 | 0 | 63.13±5.46 | 4.97±0.43 | |
| 25 | 0.46±0.29 | 1.70±0.01 | 64.12±5.86 | 0 | 64.12±5.86 | 5.05±0.46 | |
| 30 | 0.51±0.32 | 1.71±0.05 | 64.90±6.20 | 0 | 64.90±6.20 | 5.11±0.49 | |
| 35 | 0.55±0.34 | 1.72±0.05 | 65.49±6.45 | 0 | 65.49±6.45 | 5.16±0.51 | |
| 40 | 0.58±0.36 | 1.72±0.06 | 65.87±6.61 | 0 | 65.87±6.61 | 5.19±0.52 | |
| 45 | 0.59±0.37 | 1.73±0.06 | 66.06±6.69 | 0 | 66.06±6.69 | 5.20±0.53 | |
| 50 | 0.59±0.36 | 1.73±0.06 | 66.04±6.68 | 0 | 66.04±6.68 | 5.20±0.53 | |
| 55 | 0.57±0.35 | 1.73±0.06 | 65.82±6.57 | 0 | 65.82±6.57 | 5.18±0.52 | |
| S. oedipus | 0 | 0 | 1.51 | 34.19 | 0 | 34.19 | 3.38 |
| 5 | 0.31±0.07 | 1.57±0.01 | 43.21±2.13 | 0 | 43.21±2.13 | 4.28±0.21 | |
| 10 | 0.60±0.14 | 1.62±0.02 | 51.65±4.05 | 0 | 51.65±4.05 | 5.11±0.40 | |
| 15 | 0.87±0.20 | 1.67±0.04 | 59.50±5.76 | 0 | 59.50±5.76 | 5.89±0.57 | |
| 20 | 1.12±0.25 | 1.71±0.04 | 64.95±5.93 | 0 | 64.95±5.93 | 6.43±0.59 | |
| 25 | 1.35±0.30 | 1.75±0.05 | 68.51±5.75 | 0 | 68.51±5.75 | 6.78±0.57 | |
| 30 | 1.56±0.34 | 1.79±0.06 | 71.44±5.49 | 0 | 71.44±5.49 | 7.07±0.54 | |
| 35 | 1.75±0.37 | 1.82±0.07 | 74.07±5.26 | 0 | 74.07±5.26 | 7.33±0.52 | |
| 40 | 1.91±0.41 | 1.85±0.07 | 76.40±5.07 | 0 | 76.40±5.07 | 7.56±0.50 | |
| 45 | 2.06±0.44 | 1.88±0.08 | 78.43±4.93 | 0 | 78.43±4.93 | 7.76±0.49 | |
| 50 | 2.19±0.47 | 1.90±0.08 | 80.07±4.96 | 0 | 80.07±4.96 | 7.93±0.49 | |
| 55 | 2.30±0.50 | 1.92±0.09 | 81.20±5.31 | 0 | 81.20±5.31 | 8.04±0.53 | |
| ANOVA (P-values) | 0 | NA | NA | NA | NA | NA | NA |
| 5 | 0.140 | 0.010 | 0.010 | NA | 0.010 | 0.471 | |
| 10 | 0.130 | 0.214 | 0.214 | NA | 0.214 | 0.479 | |
| 15 | 0.119 | 0.725 | 0.764 | NA | 0.764 | 0.218 | |
| 20 | 0.108 | 0.846 | 0.833 | NA | 0.833 | 0.115 | |
| 25 | 0.098 | 0.587 | 0.621 | NA | 0.621 | 0.077 | |
| 30 | 0.088 | 0.431 | 0.474 | NA | 0.474 | 0.055 | |
| 35 | 0.078 | 0.331 | 0.361 | NA | 0.361 | 0.040 | |
| 40 | 0.070 | 0.263 | 0.275 | NA | 0.275 | 0.030 | |
| 45 | 0.062 | 0.213 | 0.211 | NA | 0.211 | 0.023 | |
| 50 | 0.055 | 0.177 | 0.167 | NA | 0.167 | 0.019 | |
| 55 | 0.049 | 0.150 | 0.143 | NA | 0.143 | 0.018 | |
*
Values are means ± s.e.m.
†
Bolded values indicate a significant species difference (P<0.05).
‘NA’ indicates no statistical test was applied on pre-determined values.