Neuromuscular determinants of maximum walking speed in well-functioning older adults.
Neuromuscular determinants of maximum walking speed in well-functioning older adults.
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DOI：
10.1016/j.exger.2013.01.010
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发表时间：
2013-03
影响因子：
3.9
通讯作者：
Patten, Carolynn
中科院分区：
文献类型：
--
作者：
Clark, David J.;Manini, Todd M.;Fielding, Roger A.;Patten, Carolynn
对于由神经肌肉损伤引起的与年龄相关的活动功能下降的临床评估，最大步行速度可能比通常步行速度有优势。本研究的目的是确定老年人下肢神经肌肉功能对最大步行速度的影响程度。我们招募了两组身体健康、功能良好的老年人，他们主要在最大步行速度上存在差异。我们假设，最大步行速度较慢的个体在快速收缩三头肌表面肌群（比目鱼肌（SO）和腓肠肌（MG））时，会表现出下肢肌肉大小减少、跖屈曲力产生和神经肌肉激活受损。所有参与者都被要求以通常的10米步行速度bbb1.0 m/s。如果平时与最大10m步行速度之差< 0.6 m/s，则将该个体分配到“较慢”组（n=8）。如果通常与最大10米步行速度之差为>.6 m/s，则将该个体分配到“较快”组（n=12）。在快速跖屈运动中，评估肱三头肌表面肌群的峰值力发展率（RFD）和神经肌肉激活率（肌电图上升率）。采用磁共振成像法测定右肱三头肌、股四头肌和腘绳肌群的肌肉横截面积。在参与者中，通常步行速度和最大步行速度之间的差异主要由最大步行速度决定（r= 0.85）。因此，我们报告了最大步行速度（慢速和快速分别为1.76和2.17米/秒，p< 0.001），而不是通常和最大步行速度之间的差异。慢速组的跖屈曲RFD比快速组低38% （p= 0.002）。慢速组肌电信号MG上升率比快速组低34% (p= 0.01)，而组间肌电信号SO上升率无显著差异（p= 0.73）。与我们的假设相反，在测试的肌肉群中，包括三头肌表面（p= 0.44）、四头肌（p= 0.76）和腘窝肌（p= 0.98），肌肉CSA在慢速运动中并不低于快速运动。肌电图MG上升率与RFD和10m步行速度呈正相关，与10m步行速度无关。这些发现支持了最大步行速度受到神经肌肉力量受损和三头肌表面肌群激活的限制。未来的研究应进一步评估最大步行速度在临床评估中用于检测和监测与年龄相关的功能衰退的效用。
Maximum walking speed may offer an advantage over usual walking speed for clinical assessment of age-related declines in mobility function that are due to neuromuscular impairment. The objective of this study was to determine the extent to which maximum walking speed is affected by neuromuscular function of the lower extremities in older adults. We recruited two groups of healthy, well functioning older adults who differed primarily on maximum walking speed. We hypothesized that individuals with slower maximum walking speed would exhibit reduced lower extremity muscle size and impaired plantarflexion force production and neuromuscular activation during a rapid contraction of the triceps surae muscle group (soleus (SO) and gastrocnemius (MG)). All participants were required to have usual 10-meter walking speed >1.0 m/s. If the difference between usual and maximum 10m walking speed was < 0.6 m/s, the individual was assigned to the “Slower” group (n=8). If the difference between usual and maximum 10-meter walking speed was > 0.6 m/s, the individual was assigned to the “Faster” group (n=12). Peak rate of force development (RFD) and rate of neuromuscular activation (rate of EMG rise) of the triceps surae muscle group were assessed during a rapid plantarflexion movement. Muscle cross sectional area of the right triceps surae, quadriceps and hamstrings muscle groups was determined by magnetic resonance imaging. Across participants, the difference between usual and maximal walking speed was predominantly dictated by maximum walking speed (r=.85). We therefore report maximum walking speed (1.76 and 2.17 m/s in Slower and Faster, p<.001) rather than the difference between usual and maximal. Plantarflexion RFD was 38% lower (p=.002) in Slower compared to Faster. MG rate of EMG rise was 34% lower (p=.01) in Slower than Faster, but SO rate of EMG rise did not differ between groups (p=.73). Contrary to our hypothesis, muscle CSA was not lower in Slower than Faster for the muscle groups tested, which included triceps surae (p=.44), quadriceps (p=.76) and hamstrings (p=.98). MG rate of EMG rise was positively associated with RFD and maximum 10m walking speed, but not usual 10m walking speed. These findings support the conclusion that maximum walking speed is limited by impaired neuromuscular force and activation of the triceps surae muscle group. Future research should further evaluate the utility of maximum walking speed for use in clinical assessment to detect and monitor age-related functional decline.
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影响因子：
2.4
作者：
Liu, May Q.;Anderson, Frank C.;Schwartz, Michael H.;Delp, Scott L.
通讯作者：
Delp, Scott L.
影响因子：
4
作者：
Fujiwara, Katsuo;Asai, Hitoshi;Jacobs, Jesse V.
通讯作者：
Jacobs, Jesse V.
DOI：
10.1097/00005072-197709000-00010
发表时间：
1977-01-01
影响因子：
3.2
作者：
KAWAMURA, Y;OBRIEN, P;DYCK, PJ
通讯作者：
DYCK, PJ
影响因子：
3.9
作者：
Deschenes, Michael R.;Roby, Mackenzie A.;Eason, Margaret K.;Harris, M. Brennan
通讯作者：
Harris, M. Brennan
影响因子：
9.9
作者：
Eisen, A;EntezariTaher, M;Stewart, H
通讯作者：
Stewart, H