Gallinger Tessa L, MacIntosh Brian R, Fletcher Jared R
Human Performance Laboratory, Faculty of Kinesiology, University of Calgary, Calgary, AB, Canada.
Canadian Paralympic Committee, Ottawa, ON, Canada.
Front Sports Act Living. 2025 May 13;7:1558784. doi: 10.3389/fspor.2025.1558784. eCollection 2025.
In individuals with Cerebral Palsy (CP), both muscle cross-sectional area and fascicle length are reduced, contributing to decreased muscle strength, muscle shortening velocity and muscle mechanical power output, particularly in the plantarflexor muscles. A proposed mechanism to target increased muscle mechanical power output is to incorporate high velocity training (HVT) in these individuals, to increase fascicle length via sarcomerogenesis. To determine the effects of HVT on changes in MG muscle fascicle length and that impact on changes to MG muscle force-length-velocity-power characteristics in young adults with CP.
12 young adults with CP (GMFCS I or II, 22.8 ± 6.0 years) were randomly allocated (some crossover) to no training (CP-NT, = 8), or training (CP-T, = 8). 10 recreationally trained healthy adults (HA, 22.5 ± 2.8 years) served as controls. CP-T performed 10-week training of biweekly sessions consisting of progressive intensity 10 m sprints, plyometrics and agility tasks. Triceps surae muscle force-power-velocity relationships were quantified with isokinetic dynamometry and ultrasound imaging. Data are expressed relative to pre-intervention values.
HVT resulted in a significant increase in fascicle length in CP-T (+1.92 ± 3.21 mm, < 0.005) compared to a significant decrease in CP-NT (-1.63 ± 3.00 mm, < 0.013). While HVT did not result in significant changes in maximal shortening velocity (V) or maximal peak power output (P), a large effect size for v following training in CP-T was seen (+45.2 ± 76.4%, = 0.909, = 0.452), in contrast to CP-NT (+2.9 ± 70.5%, = 0.059, = 1.00). HVT also resulted in a very large effect for P in CP-T (+35.0 ± 49.1%, = 1.093, = 0.232), but only a small effect was observed in CP-NT (+7.8 ± 49.1%, = 0.245, = 1.00). HA had significantly greater P ( < 0.001), longer resting and active fascicle lengths ( < 0.001) and greater muscle force ( < 0.001), compared to CP-T.
HVT is a feasible training intervention to increase triceps surae muscle fascicle length in individuals with CP. HVT can partially mitigate losses in P in CP compared to healthy adults. Longer HVT programs may be required to increase muscle mechanical power output in CP to levels observed in HA.
在脑瘫（CP）患者中，肌肉横截面积和肌束长度均减小，导致肌肉力量、肌肉缩短速度和肌肉机械功率输出降低，尤其是在跖屈肌中。一种旨在提高肌肉机械功率输出的建议机制是在这些个体中采用高速训练（HVT），通过肌小节生成增加肌束长度。为了确定HVT对年轻CP患者比目鱼肌肌束长度变化的影响以及对其力-长度-速度-功率特性变化的影响。
12名年轻CP患者（GMFCS I或II级，22.8±6.0岁）被随机分配（部分交叉）为无训练组（CP-NT，n = 8）或训练组（CP-T，n = 8）。10名接受过休闲训练的健康成年人（HA，22.5±2.8岁）作为对照组。CP-T组进行为期10周的训练，每两周进行一次，包括渐进强度的10米短跑、增强式训练和敏捷性任务。用等速测力法和超声成像对小腿三头肌的力-功率-速度关系进行量化。数据以干预前值为参照表示。
与CP-NT组显著减小（-1.63±3.00毫米，P<0.013）相比，HVT使CP-T组的肌束长度显著增加（+1.92±3.21毫米，P<0.005）。虽然HVT并未使最大缩短速度（V）或最大功率输出（P）发生显著变化，但CP-T组训练后v的效应量较大（+45.2±76.4%，r = 0.909，P = 0.452），而CP-NT组为（+2.9±70.5%，r = 0.059，P = 1.00）。HVT对CP-T组的P也有非常大的效应（+35.0±49.1%，r = 1.093，P = 0.232），但在CP-NT组仅观察到较小的效应（+7.8±49.1%，r = 0.245，P = 1.00）。与CP-T组相比，HA组的P显著更高（P<0.001），静息和活动肌束长度更长（P<0.001），肌肉力量更大（P<0.001）。
HVT是一种可行的训练干预措施，可增加CP患者小腿三头肌的肌束长度。与健康成年人相比，HVT可部分减轻CP患者P的损失。可能需要更长时间的HVT计划才能将CP患者的肌肉机械功率输出提高到HA组观察到的水平。
