Table 1.
Mechanical Changes Induced by High Loading in Small Animal Models
| Study Information |
Mechanical Measurements |
|||||||
|---|---|---|---|---|---|---|---|---|
| Animal | Tendon | Loading Mechanism | Comparison | CSA | Modulus | Hysteresis | Failure Load | Functional Outcome |
| Rats | ||||||||
| SD F Adult [68] | PT | Direct Tendon Loading | 7200 Cycles vs 100 Cycles | - | - | - | ||
| SD F Adult [51] | PT | Direct Tendon Loading | 7200 Cycles vs Other Groups | - | - | - | ||
| SD F Adult [87] | PT | Direct Tendon Loading | High Load Endpoint vs Baseline | - | - | - | ||
| SD M Adult [58] | AT | Eccentric Contraction | Loaded Tendon vs Unloaded Contralateral Thickness* Not CSA | - | - | - | - | |
| SD Adult * Gender not specified [50] | AT | Eccentric and Concentric Training | Eccentric (E) vs Untrained (U) | 3 | - | - | 3 | - |
| ” | AT, PT, or Tri | ” | Concentric (C) vs Untrained (U) | 3 | - | - | 3 | - |
| ” | PT | ” | Eccentric (E) vs Untrained (U) | 3 | - | - | - | |
| ” | Tri | ” | Eccentric (E) vs Untrained (U) | - | - | - | ||
| SD Adult * Gender Not Specified [75] | AT | Downhill Bipedal Running | Trained vs Untrained | - | - | - | ||
| SD M * Age Not Reported [55] | SS | Downhill Treadmill Running + Compression or Injury | Overuse (OV) vs Cage Activity | - | - | |||
| ” | SS | ” | Overuse plus Extrinsic Injury (OV+E) vs Cage Activity | 3 | - | 3 | - | |
| SD Adult * Gender not Specified [57] | SS | Downhill Treadmill Running | Overuse (OV) vs Cage Activity | - | - | |||
| ” | SS | ” | Overuse Plus Extrinsic Injury (OV+E) vs Cage Activity | - | - | |||
| ” | SS | ” | Extrinsic Injury vs Contralateral | 3 | 3 | - | 3 | - |
| SD F Adult [61] | AT | Running Wheel | Trained vs Non-Active Controls | 3 | 3 | 3 | 3 | |
| ” | ” | Vibration Strength-Trained | Vibration Strength-Trained (LVST) vs Non-Active Controls | 3 | 3 | 3 | 3 | 3 |
| ” | ” | High-Vibration Strength-Trained | High-Vibration Strength-Trained (HVST) vs Non-Active Controls | 3 | 3 | 3 | 3 | 3 |
| ” | ” | High Strength-Trained | High Strength-Trained (HST; n = 6) vs Non-Active Controls | 3 | 3 | 3 | 3 | 3 |
| W M Old and Adult [63] | CT | Climbing | Old Trained vs Old Sedentary | 3 | 3 | - | 3 | - |
| ” | SFT | Climbing | Old Trained vs Old Sedentary | 3 | 3 | - | - | |
| ” | DFT | Climbing | Old Trained vs Old Sedentary | 3 | 3 | - | 3 | - |
| ” | CT | Climbing | Young Trained vs Young Sedentary | 3 | 3 | - | - | |
| ” | SFT | Climbing | Young Trained vs Young Sedentary | 3 | 3 | - | 3 | - |
| ” | DFT | Climbing | Young Trained vs Young Sedentary | 3 | 3 | - | - | |
| SD M Adult [49] | AT | Treadmill Running (Horizontal) | Running vs Controls | 3 | - | - | ||
| W M Adult [64] | AT | Treadmill Running (Horizontal) | ST - Speed Exercise Running vs Cage Control | - | - | - | ||
| ” | ” | ” | IT - Endurance Exercise Running vs Cage Control | - | - | 3 | - | |
| ” | ” | ” | LT - Endurance Exercise Running vs Cage Control | 3 | - | - | 3 | - |
| SD M Adult [76] | TAT | Treadmill Running (Horizontal) | Running vs Cage Control Sedentary Controls | - | 3 | - | 3 | - |
| ” | FDLT | ” | Running vs Sedentary Controls | - | 3 | - | 3 | - |
| SD M Adult [62] | SS | Treadmill Running (Horizontal) | Exercise vs Cage Controls | 3 | - | - | - | |
| W M Adult [74] | AT | Strength Training | Strength Training vs Control | - | - | - | 3 | - |
| ” | AT | Swimming | Swimming vs Control | - | - | - | - | |
| Mice | ||||||||
| C57BL/6J F Adult [70] | PT | Direct Tendon Loading | 4 N Peak or 1 h vs Contralateral Control | - | 3 | - | 3 | - |
| ” | PT | ” | 6 N Peak for 1 h vs Contralateral Control | - | - | 3 | - | |
| ” | PT | ” | 4 N Peak for 2 h vs Contralateral Control | - | - | 3 | - | |
| ” | PT | ” | 4 N or 6N Peak or 1 h - Baseline vs Endpoint | - | - | - | ||
| ” | PT | ” | 4 N Peak for 2 h - Baseline vs Endpoint | - | - | - | ||
| C57BL/6 M Old and Adult [197] | Plant | Treadmill Running (Horizontal) | Running vs Sedentary | 3 | - | - | ||
Color Legend: Red - Increase; Blue - Decrease; Tan – No Change; Gray – Not Reported
SD – Sprague Dawley; W – Wistar; M – Male; F – Female; Coll – Collagan; Coll Org – Collagen Organization; GAG – gycosaminoglycan; Ag -Aggrecan; V – Versican; D – Decorin; Bn – Biglycan; Fn- Fibronectin; E – Elastin; Fmod – Fibromodulin; TNc – Tenascin-C; L - Leucin