Segal Richard L, Song Allen W
Division of Physical Therapy, Department of Rehabilitation Medicine, Emory University School of Medicine and Neuroscience Program, Emory University, Atlanta, GA, USA.
Arch Phys Med Rehabil. 2005 Oct;86(10):2013-7. doi: 10.1016/j.apmr.2005.04.012.
To determine the distribution of leg muscle activity during heel raises using magnetic resonance imaging (MRI) with special emphasis on quantifying activity across multiple axial sections and to determine if there are differences among portions of active muscles.
Pre- and postexercise (heel raise) T2-weighted time measurements were assessed by using repeated-measures analysis of variance (ANOVA) and t tests.
Laboratory and MRI suites.
Eight healthy volunteers.
Unilateral heel raises every 2 seconds for at least 60 seconds.
Percentage changes from T2-weighted magnetic resonance images of the lateral gastrocnemius, medial gastrocnemius, peroneus longus, soleus, and tibialis anterior muscles, across 10 axial sections, exercise bouts, and a pre-exercise condition.
The lateral gastrocnemius, medial gastrocnemius, peroneus longus, and soleus had significantly larger changes in T2 time from pre-exercise times than did the tibialis anterior for whole muscles as determined by using repeated-measures ANOVA and post hoc analyses. The medial gastrocnemius had a significantly greater change in T2 time than the lateral gastrocnemius. Proximal axial sections of the lateral gastrocnemius, medial gastrocnemius, and soleus had significantly larger changes in T2 time from pre-exercise than did distal sections.
This work reconfirms that multiple muscles contribute to plantarflexor forces and additionally shows an apparent proximal versus subvolume organization of activity within the gastrocnemius, medial gastrocnemius, and soleus but not the peroneus longus. This proximal versus distal organization of muscle activity needs further investigation. There may be clinical implications for therapeutic interventions that require accurate placement of electrodes such as biofeedback.
使用磁共振成像（MRI）确定足跟抬起过程中腿部肌肉活动的分布情况，特别着重于对多个轴向层面的活动进行量化，并确定活跃肌肉各部分之间是否存在差异。
通过重复测量方差分析（ANOVA）和t检验评估运动前（足跟抬起前）和运动后（足跟抬起后）T2加权时间测量值。
实验室和MRI室。
八名健康志愿者。
每2秒进行一次单侧足跟抬起，持续至少60秒。
外侧腓肠肌、内侧腓肠肌、腓骨长肌、比目鱼肌和胫骨前肌在10个轴向层面、运动回合以及运动前状态下，T2加权磁共振图像的百分比变化。
通过重复测量ANOVA和事后分析确定，对于整块肌肉而言，外侧腓肠肌、内侧腓肠肌、腓骨长肌和比目鱼肌在运动后T2时间的变化比胫骨前肌显著更大。内侧腓肠肌在T2时间上的变化比外侧腓肠肌显著更大。外侧腓肠肌、内侧腓肠肌和比目鱼肌近端轴向层面在运动后T2时间的变化比远端层面显著更大。
这项研究再次证实了多块肌肉对跖屈力有贡献，此外还显示了腓肠肌、内侧腓肠肌和比目鱼肌内活动存在明显的近端与亚体积组织差异，但腓骨长肌不存在这种差异。这种肌肉活动的近端与远端组织差异需要进一步研究。对于需要精确放置电极（如生物反馈）的治疗干预可能具有临床意义。
