Effect of Fatigue on Single-Leg Hop Landing Biomechanics

2006 ◽  
Vol 22 (4) ◽  
pp. 245-254 ◽  
Author(s):  
Karl F. Orishimo ◽  
Ian J. Kremenic
Keyword(s):  
Muscle Fatigue ◽  
Muscle Activation ◽  
Vastus Lateralis ◽  
Plantar Flexion ◽  
Thigh Muscle ◽  
Functional Improvement ◽  
Compensatory Mechanisms ◽  
Knee Motion ◽  
Muscle Activation Patterns ◽  
Knee Pathology

The objective of this study was to measure adaptations in landing strategy during single-leg hops following thigh muscle fatigue. Kinetic, kinematic, and electromyographic data were recorded as thirteen healthy male subjects performed a single-leg hop in both the unfatigued and fatigued states. To sufficiently fatigue the thigh muscles, subjects performed at least two sets of 50 step-ups. Fatigue was assessed by measuring horizontal hopping ability following the protocol. Joint motion and loading, as well as muscle activation patterns, were compared between fatigued and unfatigued conditions. Fatigue significantly increased knee motion (p = 0.012) and shifted the ankle into a more dorsiflexed position (p = 0.029). Hip flexion was also reduced following fatigue (p = 0.042). Peak extension moment tended to decrease at the knee and increase at the ankle and hip (p = 0.014). Ankle plantar flexion moment at the time of peak total support moment increased from 0.8 (N⋅m)/kg (SD, 0.6 [N⋅m]/kg) to 1.5 (N⋅m)/kg (SD, 0.8 [N⋅m]/kg) (p = 0.006). Decreased knee moment and increased knee flexion during landings following fatigue indicated that the control of knee motion was compromised despite increased activation of the vastus medialis, vastus lateralis, and rectus femoris (p = 0.014, p = 0.014, and p = 0.017, respectively). Performance at the ankle increased to compensate for weakness in the knee musculature and to maintain lower extremity stability during landing. Investigating the biomechanical adaptations that occur in healthy subjects as a result of muscle fatigue may give insight into the compensatory mechanisms and loading patterns occurring in patients with knee pathology. Changes in single-leg hop landing performance could be used to demonstrate functional improvement in patients due to training or physical therapy.

Squat Muscle Activation Patterns with Hip Rotations in Subjects with Genu Varum Deformity

2020 ◽  
Author(s):  
Mohamadreza Hatefi ◽  
Farideh Babakhani ◽  
Ramin Balouchi ◽  
Amir Letafatkar ◽  
Brian J. Wallace
Keyword(s):  
Muscle Activation ◽  
Activity Ratio ◽  
External Rotation ◽  
Vastus Lateralis ◽  
Fascia Lata ◽  
Genu Varum ◽  
Vastus Medialis ◽  
Activation Patterns ◽  
Muscle Activation Patterns ◽  
Hip Rotation

AbstractThe purpose of this study was to compare muscle activation during the squat with different hip rotations (neutral, 15, 30, and 45° of internal and external hip rotation) in subjects with and without Genu Varum deformity deformity. Surface electromyography were recorded from 32 men with (n=16) and without (n=16) Genu Varum deformity. In the Genu Varum deformity group, the squats with 30, 45 and 15° of internal rotations of the hip showed significantly greater gluteus medius activation as compared to other positions. Moreover, the tensor fascia lata activity increased with greater external rotation of the hip, and significantly more than hip internal rotations (p<0.05). For vastus medialis and vastus lateralis, both hip internal and external rotation showed a significantly greater activation compared to the neutral hip positions (p<0.05). There were significant differences in the gluteus medius:tensor fascia lata activity ratio (p=0.001) and the vastus medialis: vastus lateralis activity ratio (p=0.001) between the different hip positions in the Genu Varum deformity and healthy groups. These results demonstrate that muscle activation patterns varied significantly with the position of different hip rotation in both groups. Those with Genu Varum deformity may use this information to aid in an injury prevention strategy by choosing squat positioning that favorably alters muscle activation patterns.

scholarly journals Effects of Short-Term Training With Uncoupled Cranks in Trained Cyclists

2012 ◽  
Vol 7 (2) ◽  
pp. 113-120 ◽  
Author(s):  
Jack M. Burns ◽  
Jeremiah J. Peiffer ◽  
Chris R. Abbiss ◽  
Greig Watson ◽  
Angus Burnett ◽  
...  
Keyword(s):  
Muscle Activation ◽  
Vastus Lateralis ◽  
Biceps Femoris ◽  
Training Group ◽  
Recovery Phase ◽  
Muscle Recruitment ◽  
Short Term ◽  
Activation Patterns ◽  
Gross Efficiency ◽  
Muscle Activation Patterns

Purpose:Manufacturers of uncoupled cycling cranks claim that their use will increase economy of motion and gross efficiency. Purportedly, this occurs by altering the muscle-recruitment patterns contributing to the resistive forces occurring during the recovery phase of the pedal stroke. Uncoupled cranks use an independent-clutch design by which each leg cycles independently of the other (ie, the cranks are not fixed together). However, research examining the efficacy of training with uncoupled cranks is equivocal. The purpose of this study was to determine the effect of short-term training with uncoupled cranks on the performance-related variables economy of motion, gross efficiency, maximal oxygen uptake (VO2max), and muscle-activation patterns.Methods:Sixteen trained cyclists were matched-paired into either an uncoupled-crank or a normal-crank training group. Both groups performed 5 wk of training on their assigned cranks. Before and after training, participants completed a graded exercise test using normal cranks. Expired gases were collected to determine economy of motion, gross efficiency, and VO2max, while integrated electromyography (iEMG) was used to examine muscle-activation patterns of the vastus lateralis, biceps femoris, and gastrocnemius.Results:No significant changes between groups were observed for economy of motion, gross efficiency, VO2max, or iEMG in the uncoupled- or normal-crank group.Conclusions:Five weeks of training with uncoupled cycling cranks had no effect on economy of motion, gross efficiency, muscle recruitment, or VO2max compared with training on normal cranks.

Comparative Muscle Activation Patterns of Healthy Control Limbs and Contralateral Limbs in ACL Reconstruction

2012 ◽  
Author(s):  
Chelsea Marsh ◽  
Scott Tashman
Keyword(s):  
Acl Reconstruction ◽  
Muscle Activation ◽  
Vastus Lateralis ◽  
Rectus Femoris ◽  
Activation Patterns ◽  
Muscle Activation Patterns ◽  
Healthy Control ◽  
Reconstructed Knee

ACL reconstruction (ACLr) has been found to restore the functionality and mobility of those afflicted with ACL tears. In the process of this restoration, previous work has shown alterations in the activity of the musculature surrounding the reconstructed knee [1]. Specifically, at 5 months post-op, the gastrocnemius, vastus lateralis, and rectus femoris demonstrate significantly different activation patterns. These differences raise the question if the reconstructed leg is the only limb affected by ACLr.

Knee motion and muscle activation patterns are altered in hip osteoarthritis: The effect of severity on walking mechanics

2018 ◽  
Vol 59 ◽  
pp. 1-7 ◽  
Author(s):  
Derek Rutherford ◽  
Lindsey Buckingham ◽  
Janice Moreside ◽  
Ivan Wong ◽  
Glen Richardson
Keyword(s):  
Muscle Activation ◽  
Hip Osteoarthritis ◽  
Knee Motion ◽  
Activation Patterns ◽  
Muscle Activation Patterns

scholarly journals Individuals have unique muscle activation signatures as revealed during gait and pedaling

2019 ◽  
Vol 127 (4) ◽  
pp. 1165-1174 ◽  
Author(s):  
François Hug ◽  
Clément Vogel ◽  
Kylie Tucker ◽  
Sylvain Dorel ◽  
Thibault Deschamps ◽  
...  
Keyword(s):  
Machine Learning ◽  
Muscle Activation ◽  
Vastus Lateralis ◽  
Support Vector ◽  
Experimental Session ◽  
Learning Approach ◽  
Classification Rate ◽  
Activation Patterns ◽  
Muscle Activation Patterns ◽  
Machine Learning Approach

Although it is known that the muscle activation patterns used to produce even simple movements can vary between individuals, these differences have not been considered to prove the existence of individual muscle activation strategies (or signatures). We used a machine learning approach (support vector machine) to test the hypothesis that each individual has unique muscle activation signatures. Eighty participants performed a series of pedaling and gait tasks, and 53 of these participants performed a second experimental session on a subsequent day. Myoelectrical activity was measured from eight muscles: vastus lateralis and medialis, rectus femoris, gastrocnemius lateralis and medialis, soleus, tibialis anterior, and biceps femoris -long head. The classification task involved separating data into training and testing sets. For the within-day classification, each pedaling/gait cycle was tested using the classifier, which had been trained on the remaining cycles. For the between-day classification, each cycle from day 2 was tested using the classifier, which had been trained on the cycles from day 1. When considering all eight muscles, the activation profiles were assigned to the corresponding individuals with a classification rate of up to 99.28% (2,353/2,370 cycles) and 91.22% (1,341/1,470 cycles) for the within-day and between-day classification, respectively. When considering the within-day classification, a combination of two muscles was sufficient to obtain a classification rate >80% for both pedaling and gait. When considering between-day classification, a combination of four to five muscles was sufficient to obtain a classification rate >80% for pedaling and gait. These results demonstrate that strategies not only vary between individuals, as is often assumed, but are unique to each individual. NEW & NOTEWORTHY We used a machine learning approach to test the uniqueness and robustness of muscle activation patterns. We considered that, if an algorithm can accurately identify participants, one can conclude that these participants exhibit discernible differences and thus have unique muscle activation signatures. Our results show that activation patterns not only vary between individuals, but are unique to each individual. Individual differences should, therefore, be considered relevant information for addressing fundamental questions about the control of movement.

scholarly journals Daily physical function and frailty in persons with Parkinson's disease: a focus on females

2013 ◽  
Vol 38 (3) ◽  
pp. 358-358
Author(s):  
Kaitlyn P. Roland
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Physical Function ◽  
Muscle Fatigue ◽  
Muscle Activation ◽  
Functional Independence ◽  
Extensive Literature ◽  
Physically Active ◽  
Muscle Activation Patterns ◽  
Physiological Capacity

Persons with Parkinson's disease (PD) are often excluded from frailty studies, and thus little is known about how frailty influences decline in physiological capacity in persons with PD. Impaired physiological capacity impacts the ability to remain physically active, which reduces physical function that is necessary for independent living. The overall purpose of this dissertation was to examine physiological capacity (i.e., muscle activation patterns) and physical activity in males and females with PD during routine daily activities to determine whether they influence physical function and frailty. An extensive literature review of sex differences in PD highlighted that greater declines in gait speed, balance, and motor function occur in females compared with males. This dissertation demonstrated persons with PD, especially females with PD, were weaker and have less muscle quiescence, as measured with gaps in the electromyography, compared with controls and males with PD. These results provide insight into mechanisms (i.e., physiological capacity) that determine PD and sex-related declines in functional performance. In addition, greater muscle activity and less quiescence in females with PD may perpetuate frailty through increased muscle fatigue and slowness of movement. Females with PD are more vulnerable to prefrailty than males and factors that are associated with frailty are quality of life (QoL) and self-reported exhaustion. The neuromuscular changes associated with frailty exacerbate PD, which may create greater muscle fatigue that results in self-reported exhaustion. In conclusion, research presented within this dissertation demonstrates that addressing frailty in PD is important, especially in females who are at greater risk for functional decline. This research presents new knowledge by suggesting that frail females with PD remain physically active during daily life and that disease management may better reflect frailty than disease severity or duration. Understanding how frailty concurrently exists with PD and how these conditions progress within the aging adult may enhance identification and implementation of management strategies aimed at improving functional independence and QoL.

scholarly journals Differences of Thigh Muscle Activation During Various Squat Exercise on Stable and Unstable Surfaces

2021 ◽  
Vol 30 (3) ◽  
pp. 387-395
Author(s):  
Soojin Kim ◽  
Joo-Hyun Lee ◽  
Jihye Heo ◽  
Eunwook Chang
Keyword(s):  
Muscle Activity ◽  
Repeated Measures ◽  
Muscle Activation ◽  
Vastus Lateralis ◽  
Rectus Femoris ◽  
Biceps Femoris ◽  
Quadriceps Muscle ◽  
Thigh Muscle ◽  
Unstable Surface ◽  
Co Activation

PURPOSE: The purpose of this study was to compare thigh muscle activities and muscle co-activation when performing squats, wall squats, and Spanish squats on stable and unstable ground.METHODS: Twenty-two healthy male subjects (age: 22.50±2.70 years, height: 178.72±6.04 cm, mass: 76.50±6.80 kg, body mass index: 24.00±2.10 kg/m2, and Godin activity questionnaire: 56.30±24.10) voluntarily participated in the study. All of the participants performed three different squat exercises on the floor and the BOSU ball with an electromyograph attached to each participant’s quadriceps (rectus femoris, RF; vastus lateralis, VL; and vastus medialis, VM) and hamstrings (biceps femoris, BF; semitendinosus, ST; and semimembranosus, SM). Repeated measures of analysis of variance were utilized to compare muscle activity during the three squats exercises by floor type.RESULTS: RF (p<.001, η2=.689), VL (p<.001, η2=.622), and VM (p=.002, η2=.375) showed significant differences between exercises. Spanish squats yielded greater BF activity than did wall squats (p=.018, η2=.269). ST yielded greater muscle activity with the BOSU ball than on the floor (p=.018, η2=.269). Finally, there was a significant ground exercise interaction effect on the co-activation, showing greater muscle co-activation with Spanish squats on the BOSU ball compared to squats, squats on the BOSU ball, and wall squat on the BOSU ball.CONCLUSIONS: The findings of this study indicate that Spanish squats could be an effective exercise option for the facilitation of RF, VL, VM, and BF muscle activation. In particular, performing Spanish squats on an unstable surface could be useful for patients who need to improve their quadriceps muscle activation.

scholarly journals How Do Violinists Adapt to Dynamic Assistive Support? A Study Focusing on Kinematics, Muscle Activity, and Musical Performance

2021 ◽  
pp. 001872082110334
Author(s):  
Clara Ziane ◽  
Benjamin Michaud ◽  
Mickaël Begon ◽  
Fabien Dal Maso
Keyword(s):  
Muscle Fatigue ◽  
Injury Risk ◽  
Muscle Activation ◽  
Musical Performance ◽  
Experimental Conditions ◽  
Muscle Activation Patterns ◽  
Left Elbow ◽  
Repetitive Nature ◽  
Injury Risk Factor ◽  
Muscle Activations

Objective Assessing violinists’ motor and musical performance adaptations to dynamic assistive support (DAS) provided by a passive device, using a force-field adaptation paradigm. Background Up to 93% of instrumentalists are affected by musculoskeletal injuries and particularly violinists. The repetitive nature of their work may lead to muscle fatigue, an injury risk factor. DAS has been used in occupational settings to minimize muscle activations and limit fatigue accumulation. DAS may however affect motor and musical performance. Method Fifteen expert violinists were equipped with reflective markers and surface and intramuscular electromyography (EMG) sensors. Movements, muscle activations, and sound were recorded while participants completed three experimental conditions for which they continuously played a 13-s musical excerpt: Control (no DAS), Adaptation (DAS), and Washout (no DAS). DAS was applied at the left elbow (violin-holding side). Conditions were repeated 1 week later. Participants later listened to their own audio recordings playing with and without DAS and blindly assessed their performances. Linear mixed models were used to compare DAS and no-DAS conditions’ kinematic, EMG, and musical performance data. Results DAS perturbed user kinematics but reduced mean activations of left medial deltoid and superior trapezius. Joint kinematic and muscle activation patterns between DAS and no DAS conditions however remained similar. Musical performance was unchanged with DAS. Conclusion Though DAS modified violinists’ upper-limb configurations, resulting kinematics were not detrimental to musical performance. Reduced muscle activations with DAS could contribute to lessening muscle fatigue. Application Although its effect on muscle fatigue should be further investigated, DAS might be useful in preventing violinists’ injuries.

Lower-Extremity Muscle Activation during the Star Excursion Balance Tests

2001 ◽  
Vol 10 (2) ◽  
pp. 93-104 ◽  
Author(s):  
Jennifer Erin Earl ◽  
Jay Hertel
Keyword(s):  
Lower Extremity ◽  
Repeated Measures ◽  
Muscle Activation ◽  
Vastus Lateralis ◽  
Biceps Femoris ◽  
Emg Activity ◽  
Muscle Activation Patterns ◽  
Lower Extremity Muscle ◽  
Balance Tests ◽  
Integrated Emg

Objective:To identify integrated EMG (I-EMG) activity of 6 lower-extremity muscles during the 8 Star Excursion Balance Tests (SEBTs).Design and Setting:Repeated measures, laboratory setting.Subjects:10 healthy young adults.Interventions:The SEBTs require the subject to balance on the stance leg and maximally reach with the contralateral foot along each of 8 lines extending from a common axis at 45° intervals.Measures:I-EMG activity of the vastus medialis obliquus (VMO), vastus lateralis (VL), medial hamstring (MH), biceps femoris (BF), anterior tibialis (AT), and gas-trocnemius.Results:Significant differences were found in all muscles (P < .05) except the gastrocnemius (P = .08). VMO and VL activity tended to be greatest with anteriorly directed excursions, whereas the MH and BF activity were greatest with posteriorly directed excursions. AT activity was lowest with the lateral excursion.Conclusions:Performance of the different SEBTs results in different lower-extremity muscle-activation patterns.

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