Selective activation of tibialis posterior: Evaluation by magnetic resonance imaging
Selective activation of tibialis posterior: Evaluation by magnetic resonance imaging
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DOI：
10.1249/01.mss.0000126385.12402.2e
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发表时间：
2004-05-01
期刊：
影响因子：
--
通讯作者：
Terk, M
中科院分区：
文献类型：
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作者：
Kulig, K;Burnfield, JM;Terk, M
目的：确定哪种运动最能选择性和有效地激活胫骨后肌。方法：5名健康成人（2男3女，平均年龄31岁），足弓指数（AI）与正常值相差1个标准差以内，进行3次运动，间隔1周。练习为：1)闭链抵抗足内收（足内收），2)单侧足跟抬高（脚跟抬高），3)开链抵抗足旋（足旋）。使用1.5 t MRI系统在运动前后立即获得磁共振跨轴图像。运动前后信号强度的变化比较了五块肌肉：胫骨后肌、胫骨前肌、腓肠肌内侧、比目鱼肌和腓骨长肌。运动后信号强度归一化为基线运动前信号强度。结果：每次运动后胫骨后肌信号强度均增加。最大的TP增加（50 +/- 6%）发生在足内收后，而其他肌肉的平均增加小于5%。提跟运动后，TP信号强度增加27%(+/- 11%)，比目鱼肌39%(+/- 8%)，腓骨长肌57%(+/- 14%)，腓骨内侧肌99%（+/- 12%）。胫骨前肌信号强度下降4%（+/- 2%）。足部旋后，TP信号强度增加26%(+/- 7%)，而其他肌肉的平均变化小于10%。多变量方差分析显示，不同运动之间的肌肉激活有显著差异。后置分析显示，足内收时TP的激活程度高于足旋时（P = 0.021）。结论：在AI正常的个体中，TP在足内收时被选择性激活，且最有效。了解选择性激活肌肉是必要的，为肌肉强化和/或肌腱康复提供最佳环境。
Purpose: To determine which exercise most selectively and effectively activates tibialis posterior. Methods: Five healthy adults (two men, three women; mean age 31 yr) with an Arch Index (AI) within 1 SD from norm performed three exercises, separated by 1-wk intervals. The exercises were: 1) closed chain resisted foot adduction (foot adduction), 2) unilateral heel raise (heel raise), and 3) open chain resisted foot supination (foot supination). Magnetic resonance transaxial images were obtained immediately before and after exercise using a 1.5-T MRI system. Changes in pre-to postexercise signal intensity were compared across five muscles: tibialis posterior, tibialis anterior, medial gastrocnemius, soleus, and peroneus longus. Postexercise signal intensity was normalized to baseline preexercise signal intensity. Results: Tibialis posterior signal intensity increased after each exercise. The greatest TP increase (50 +/- 6%) occurred after foot adduction, whereas the mean increase in the other muscles was less than 5%. After the heel raise exercise, the signal intensity increase in TP was 27% (+/- 11%), soleus 39% (+/- 8%), peroneus longus 57% (+/- 14%), and medial gastrocnemius 99% (+/- 12%). The signal intensity of tibialis anterior decreased 4% (+/- 2%). After foot supination, the TP signal intensity increased 26% (+/- 7%), whereas the mean change in the other muscles was less than 10%. Multivariate analyses of variance revealed a significant difference in muscle activation between exercises. Posthoc analysis showed greater activation of TP during foot adduction than foot supination (P = 0.021). Conclusion: In individuals with a normal AI TP was activated selectively and most effectively during foot adduction. Knowledge of selective activation of a muscle is necessary to provide an optimal environment for muscle strengthening and/or tendon rehabilitation.