Bellenfant Kara B, Robbins Gracie L, Rogers Rebecca R, Kopec Thomas J, Ballmann Christopher G
Department of Kinesiology, Samford University, Birmingham, AL 35229, USA.
J Funct Morphol Kinesiol. 2021 Feb 9;6(1):16. doi: 10.3390/jfmk6010016.
The purpose of this study was to investigate the effects of how limb dominance and joint immobilization alter markers of physical demand and muscle activation during ambulation with axillary crutches. In a crossover, counterbalanced study design, physically active females completed ambulation trials with three conditions: (1) bipedal walking (BW), (2) axillary crutch ambulation with their dominant limb (DOM), and (3) axillary crutch ambulation with their nondominant limb (NDOM). During the axillary crutch ambulation conditions, the non-weight-bearing knee joint was immobilized at a 30-degree flexion angle with a postoperative knee stabilizer. For each trial/condition, participants ambulated at 0.6, 0.8, and 1.0 mph for five minutes at each speed. Heart rate (HR) and rate of perceived exertion (RPE) were monitored throughout. Surface electromyography (sEMG) was used to record muscle activation of the medial gastrocnemius (MG), soleus (SOL), and tibialis anterior (TA) unilaterally on the weight-bearing limb. Biceps brachii (BB) and triceps brachii (TB) sEMG were measured bilaterally. sEMG signals for each immobilization condition were normalized to corresponding values for BW.HR ( < 0.001) and RPE ( < 0.001) were significantly higher for both the DOM and NDOM conditions compared to BW but no differences existed between the DOM and NDOM conditions ( > 0.05). No differences in lower limb muscle activation were noted for any muscles between the DOM and NDOM conditions ( > 0.05). Regardless of condition, BB activation ipsilateral to the ambulating limb was significantly lower during 0.6 mph ( = 0.005) and 0.8 mph ( = 0.016) compared to the same speeds for BB on the contralateral side. Contralateral TB activation was significantly higher during 0.6 mph compared to 0.8 mph ( = 0.009) and 1.0 mph ( = 0.029) irrespective of condition. In conclusion, limb dominance appears to not alter lower limb muscle activation and walking intensity while using axillary crutches. However, upper limb muscle activation was asymmetrical during axillary crutch use and largely dependent on speed. These results suggest that functional asymmetry may exist in upper limbs but not lower limbs during assistive device supported ambulation.
本研究的目的是调查在使用腋拐行走过程中，肢体优势和关节固定如何改变身体需求和肌肉激活的指标。在一项交叉、平衡的研究设计中，身体活跃的女性完成了三种情况下的行走试验：（1）双足行走（BW），（2）用优势肢体使用腋拐行走（DOM），以及（3）用非优势肢体使用腋拐行走（NDOM）。在使用腋拐行走的情况下，非负重膝关节用术后膝关节稳定器固定在30度屈曲角度。对于每个试验/情况，参与者在每种速度下以0.6、0.8和1.0英里/小时的速度行走5分钟。全程监测心率（HR）和自觉用力程度（RPE）。表面肌电图（sEMG）用于记录负重肢体上腓肠肌内侧头（MG）、比目鱼肌（SOL）和胫骨前肌（TA）的肌肉激活情况。双侧测量肱二头肌（BB）和肱三头肌（TB）的sEMG。将每种固定情况下的sEMG信号归一化为BW的相应值。与BW相比，DOM和NDOM情况下的HR（<0.001）和RPE（<0.001）均显著更高，但DOM和NDOM情况之间不存在差异（>0.05）。DOM和NDOM情况之间，任何肌肉的下肢肌肉激活均无差异（>0.05）。无论情况如何，与对侧相同速度下的BB相比，行走肢体同侧的BB在0.6英里/小时（=0.005）和0.8英里/小时（=0.016）时的激活均显著降低。无论情况如何，对侧TB在0.6英里/小时时的激活均显著高于0.8英里/小时（=0.009）和1.0英里/小时（=0.029）。总之，在使用腋拐时，肢体优势似乎不会改变下肢肌肉激活和行走强度。然而，在使用腋拐过程中，上肢肌肉激活是不对称的，并且在很大程度上取决于速度。这些结果表明，在辅助器械支持的行走过程中，上肢可能存在功能不对称，但下肢不存在。
