scholarly journals Fibre operating lengths of human lower limb muscles during walking

2011 ◽  
Vol 366 (1570) ◽  
pp. 1530-1539 ◽  
Author(s):  
Edith M. Arnold ◽  
Scott L. Delp
Keyword(s):  
Muscle Fibre ◽  
Lower Limb ◽  
Muscle Activation ◽  
Fibre Length ◽  
Musculoskeletal Model ◽  
Muscle Fibres ◽  
Joint Angles ◽  
Moment Arms ◽  
Lower Limb Muscles ◽  
Limb Muscles

Muscles actuate movement by generating forces. The forces generated by muscles are highly dependent on their fibre lengths, yet it is difficult to measure the lengths over which muscle fibres operate during movement. We combined experimental measurements of joint angles and muscle activation patterns during walking with a musculoskeletal model that captures the relationships between muscle fibre lengths, joint angles and muscle activations for muscles of the lower limb. We used this musculoskeletal model to produce a simulation of muscle–tendon dynamics during walking and calculated fibre operating lengths (i.e. the length of muscle fibres relative to their optimal fibre length) for 17 lower limb muscles. Our results indicate that when musculotendon compliance is low, the muscle fibre operating length is determined predominantly by the joint angles and muscle moment arms. If musculotendon compliance is high, muscle fibre operating length is more dependent on activation level and force–length–velocity effects. We found that muscles operate on multiple limbs of the force–length curve (i.e. ascending, plateau and descending limbs) during the gait cycle, but are active within a smaller portion of their total operating range.

Analysis of the activation modalities of the lower limb muscles during walking

2020 ◽  
Vol 28 (5) ◽  
pp. 521-532 ◽  
Author(s):  
Wei Li ◽  
Zhongli Li ◽  
Shuyan Qie ◽  
Huaqing Yang ◽  
Xuemei Chen ◽  
...  
Keyword(s):  
Lower Limb ◽  
Muscle Activation ◽  
Gait Cycle ◽  
Lower Limbs ◽  
Medial Gastrocnemius ◽  
Peak Time ◽  
Lower Limb Muscles ◽  
Emg Signal ◽  
Limb Muscles ◽  
Activation Intervals

BACKGROUND: Walking is a basic human activity and many orthopedic diseases can manifest with gait abnormalities. However, the muscle activation intervals of lower limbs are not clear. OBJECTIVE: The aim of this study was to explore the contraction patterns of lower limb muscles by analyzing activation intervals using surface electromyography (SEMG) during walking. METHODS: Four muscles including the tibialis anterior (TA), lateral gastrocnemius (LG), medial gastrocnemius (MG), and rectus femoris (RF) of bilateral lower extremity of 92 healthy subjects were selected for SEMG measurements. The number of activations (activation intervals) and the point of the highest root mean square (RMS) EMG signal in the percentage of the gait cycle (GC) were used to analyze muscle activities. RESULTS: The majority of TA and RF showed two activation intervals and both gastrocnemius parts three activation intervals during walking. The point of the highest RMS EMG signal in the percentage of the GC for TA, LG, MG and RF are 5%, 41%, 40%, and 8%, respectively. The activation intervals were mostly affected by age, height, different genders and bilateral limbs. CONCLUSION: This study identified the different activation intervals (four for each muscle) and the proportion of healthy adults in which they occurred during the normal gait cycle. These different activation intervals provided a new insight to evaluate the function of nerves and muscles. In addition, the activation interval and RMS peak time proposed in this study can be used as new parameters for gait analysis.

scholarly journals Visualization of walking speed variation-induced synchronized dynamic changes in lower limb joint angles and activity of trunk and lower limb muscles with a newly developed gait analysis system

2018 ◽  
Vol 26 (3) ◽  
pp. 230949901880668 ◽  
Author(s):  
Kousei Miura ◽  
Hideki Kadone ◽  
Masao Koda ◽  
Keita Nakayama ◽  
Hiroshi Kumagai ◽  
...  
Keyword(s):  
Gait Analysis ◽  
Hip Joint ◽  
Lower Limb ◽  
Three Dimensional ◽  
Lower Limbs ◽  
Joint Angles ◽  
Dynamic Changes ◽  
Maximum Flexion ◽  
Lower Limb Muscles ◽  
Limb Muscles

Purpose: To evaluate a newly developed system for dynamic analysis of gait kinematics and muscle activity. Methods: We recruited 10 healthy men into this study. Analyses of three-dimensional motion and wireless surface electromyogram (EMG) were integrated to achieve synchronous measurement. The participants walked continuously for 10 min under two conditions: comfortable and quick pace. Outcome measures were joint angles of the lower limbs determined from reflective markers and myoelectric activity of trunk and lower limbs determined from EMG sensors, comparing comfortable and quick gait pace. Results: Lower limb joint angle was significantly greater at the quick pace (maximum flexion of the hip joint: 4.1°, maximum extension of hip joint: 2.3°, and maximum flexion of the knee joint while standing: 7.4°). The period of maximum flexion of the ankle joint during a walking cycle was 2.5% longer at a quick pace. EMG amplitudes of all trunk muscles significantly increased during the period of support by two legs (cervical paraspinal: 55.1%, latissimus dorsi: 31.3%, and erector spinae: 32.6%). EMG amplitudes of quadriceps, femoral biceps, and tibialis anterior increased significantly by 223%, 60.9%, and 67.4%, respectively, between the periods of heel contact and loading response. EMG amplitude of the gastrocnemius significantly increased by 102% during the heel-off period. Conclusion: Our gait analysis synchronizing three-dimensional motion and wireless surface EMG successfully visualized dynamic changes in lower limb joint angles and activity of trunk and lower limb muscles induced by various walking speeds.

scholarly journals Electromyographic Assessment of the Lower Leg Muscles during Concentric and Eccentric Phases of Standing Heel Raise

Healthcare ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 465
Author(s):  
Ukadike C. Ugbolue ◽  
Emma L. Yates ◽  
Kerensa Ferguson ◽  
Scott C. Wearing ◽  
Yaodong Gu ◽  
...  
Keyword(s):  
Lower Limb ◽  
Muscle Activation ◽  
Lower Limbs ◽  
Emg Activity ◽  
Neutral Position ◽  
Muscle Action ◽  
Gastrocnemius Medialis ◽  
Muscle Activation Patterns ◽  
Lower Limb Muscles ◽  
Limb Muscles

Only a small number of muscle activation patterns from lower limbs have been reported and simultaneous muscle activation from several lower limb muscles have not yet been investigated. The purpose of this study was to examine any gender differences in surface electromyography (EMG) activity from six recorded lower limb muscles of the dominant limb at baseline (i.e., with the foot placed flat on the floor and in the neutral position), and during concentric and eccentric phases when performing a heel raise task. In total, 10 females and 10 males performed a standing heel raise task comprising of three continuous phases: baseline, unloading (concentric muscle action), and loading (eccentric muscle action) phases. Muscle activation from six muscles (gastrocnemius medialis, gastrocnemius lateralis, soleus, tibialis anterior, peroneus longus, and peroneus brevis) were measured using the Myon 320 EMG System. Root mean squared values of each muscle were calculated for each phase. Descriptive and inferential statistics were incorporated into the study. Statistically significant p values were set at 0.05. The results showed no significant differences between baseline, concentric, and eccentric phases with respect to each of the muscles investigated. Except for the gastrocnemius medialis at baseline and concentric phases, no significant differences were observed between genders or contractions. The data suggests that gender does not significantly influence the eccentric phase during the standing heel raise task.

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