The Use of MRI to Evaluate Posterior Thigh Muscle Activity and Damage During Nordic Hamstring Exercise

2013 ◽  
Vol 27 (12) ◽  
pp. 3426-3435 ◽  
Author(s):  
Jurdan Mendiguchia ◽  
Asier L. Arcos ◽  
Mirian A. Garrues ◽  
Gregory D. Myer ◽  
Javier Yanci ◽  
...  
Keyword(s):  
Muscle Activity ◽  
Thigh Muscle ◽  
Posterior Thigh

Thigh muscle activity during maximum-height jumps by cats

1985 ◽  
Vol 53 (4) ◽  
pp. 979-994 ◽  
Author(s):  
F. E. Zajac
Keyword(s):  
Muscle Activity ◽  
Force Plate ◽  
Biceps Femoris ◽  
Thigh Muscle ◽  
Body Lift ◽  
Knee Flexor ◽  
Posterior Thigh ◽  
Thigh Muscles ◽  
Flexor Muscles ◽  
Lift Off

Cats were trained to jump from a force plate and touch a cotton ball suspended as high as 1.6 m. Force-plate reaction forces and double-joint hamstring muscle activity observed early in propulsion varied from one maximal jump to another. This variability is consistent with theory (31, 32, 42); that is, different coordination strategies can be implemented prior to the heels losing contact with the force plate (heel-off). Single-joint hip extensor and double-joint posterior thigh (hip extensor-knee flexor) muscles were coactivated prior to heel-off. This coactivation is probably partially responsible for the observed backward rotation of the trunk. Forepaws, observed to contact the force plate prior to heel-off, probably assist the hindlimbs in generating trunk rotation. Both single-joint knee extensor and hip extensor muscles exhibited greatest activation between heel-off and body lift-off. Single-joint flexor muscles were inactive throughout propulsion. Double-joint posterior thigh muscles were deactivated at heel-off and remained inactivated until lift-off. These observations agree with the theoretical notion that muscles should be either fully activated, inactivated, or switched from one extreme to the other (i.e., bang-bang control) between heel-off and body lift-off (31, 32, 42, 44). All seven muscles studied shortened while activated. Using computations based on muscle geometry, fiber architecture, and joint angle trajectories, I propose that sarcomeres shorten along the flat and ascending regions of the force-length curve. De- and inactivation of double-joint posterior thigh muscles between heel-off and lift-off coincided with muscle stretch. The reason for inactivation of these muscles is that the negative work that would have been generated had these muscles stayed activated would have hindered propulsion. Contractions preceded by active stretch were not observed. Enhancement of positive work by previous storage of energy in elastic musculotendinous structures is thus not used by cat thigh musculature in jumps starting from the squat. Adductor femoris, semimembranosus anterior, and biceps femoris anterior muscles were activated synergistically as one group yet differently from the synergistic activation of gracilis, semitendinosus, and biceps femoris posterior muscles. The separation of these muscles into two groups based on their activation patterns during jumping is compatible with the classification of these muscles into hip extensor and knee flexor muscle groups, respectively, based on their reflex patterns (37), spinal cord reflex connectivity (18, 30), and firing patterns during locomotion (20).(ABSTRACT TRUNCATED AT 400 WORDS)

Antagonist thigh-muscle activity in 6-to-8-year-old children assessed by surface EMG during walking

2017 ◽  
Author(s):  
Francesco Di Nardo ◽  
Annachiara Strazza ◽  
Alessandro Mengarelli ◽  
Serena Ercolani ◽  
Laura Burattini ◽  
...  
Keyword(s):  
Muscle Activity ◽  
Surface Emg ◽  
Thigh Muscle

Bilateral Biomechanical Asymmetry During 30 Seconds Isokinetic Sprint-Cycling Exercise

2015 ◽  
Vol 6 (1) ◽  
pp. 1-14
Author(s):  
Indrek Rannama ◽  
Kristjan Port
Keyword(s):  
Muscle Activity ◽  
Directional Asymmetry ◽  
Thigh Muscle ◽  
Vastus Lateralis Muscle ◽  
Median Frequency ◽  
Cycling Exercise ◽  
Emg Amplitude ◽  
Competitive Cyclists ◽  
Bilateral Differences ◽  
Leg Dominance

Abstract The purpose of present study was to examine the bilateral differences of pedalling kinetics and thigh muscle activity patterns according to leg dominance during the 30 seconds maximal cycling exercise and to analyse the relationships between asymmetries of pedalling kinetics and muscle activity. Methods: The pedalling power (POW), power production smoothness (PS) and EMG of VL, RF and BF of 17 competitive cyclists (19.2±1.6y.; 1.82±0.07m; 74.1±8.2kg) were measured bilaterally during maximal 30s isokinetic (cadence limit 100 rpm) seated cycling exercise. The dynamics of POW, PS and normalized EMG-RMS amplitude and median frequency (MF) of dominant (DO) and non-dominant (ND) side were measured. The directional asymmetry indexes (AI%) between DO and ND side were computed and compared with student t-test for paired samples. Correlation analyse between AI(%) of pedalling kinetics and EMG patterns was made. Results: The DO side POW and PS values were significantly (p<0.05) higher than ND during the all exercise time (except POW between 5-10 sec). No significant bilateral differences were found between normalized EMG amplitude values. The AI(%) of POW and PS were significantly lowered during the exercise. Significant correlations were found between AI (%)-s of PS and VL EMG MFr (r=-0.64) and between AI(%)-s of POW and VL normalized EMG amplitude (r=0.63).Conclusions: Results of the present study indicate that during 30 seconds maximal intensity cycling does exist leg dominance dependent asymmetries in pedalling power patterns, which decreased during the exercise and was related with bilaterally asymmetry of vastus lateralis muscle firing patterns.

The role of active knee rom for posterior thigh muscle injuries prevention

2011 ◽  
Vol 45 (2) ◽  
pp. e1-e1
Author(s):  
A. Siozos ◽  
N. Malliaropoulos ◽  
D. Tsiftsogloy ◽  
D. Xristodoulou
Keyword(s):  
Thigh Muscle ◽  
Muscle Injuries ◽  
Posterior Thigh

Tibiofemoral Joint-Surface Motions in Weight-Bearing and Non-Weight-Bearing Movement

2003 ◽  
Vol 12 (2) ◽  
pp. 143-161 ◽  
Author(s):  
John H. Hollman ◽  
Robert H. Deusinger ◽  
Linda R. Van Dillen ◽  
Dequan Zou ◽  
Scott D. Minor ◽  
...  
Keyword(s):  
Outcome Measures ◽  
Muscle Activity ◽  
Repeated Measures ◽  
Weight Bearing ◽  
Knee Extension ◽  
Thigh Muscle ◽  
Joint Surface ◽  
Emg Activity ◽  
Sliding Motion ◽  
Type Design

Context:Analyses of the path of instant center of rotation (PICR) can be used to infer joint-surface rolling and sliding motion (arthrokinematics). Previous PICR research has not quantified arthrokinematics during weight-bearing (WB) movement conditions or studied the association of muscle activity with arthrokinematics.Objective:To examine tibiofemoral arthrokinematics and thigh-muscle EMG during WB and non-weight-bearing (NWB) movement.Design:2 x 9 repeated-measures experiment.Setting:Laboratory.Participants:11 healthy adults (mean age 24 years).Main Outcome Measures:Tibiofemoral percentage rolling arthrokinematics and quadriceps: hamstring EMG activity.Results:WB percentage rolling (76.0% ± 4.7%) exceeded that of NWB (57.5% ± 1.8%) through terminal knee extension (F8,80= 8.99,P< .001). Quadriceps:hamstring EMG ratios accounted for 45.1% and 34.7% of the variance in arthrokinematics throughout the WB and NWB movement conditions, respectively (P< .001).Conclusions:More joint-surface rolling occurs through terminal knee extension during WB movement and is associated with an increase in hamstring activity.

Mutability of Bifunctional Thigh Muscle Activity in Pedaling due to Contralateral Leg Force Generation

2002 ◽  
Vol 88 (3) ◽  
pp. 1308-1317 ◽  
Author(s):  
S. A. Kautz ◽  
D. A. Brown ◽  
H.F.M. Van der Loos ◽  
F. E. Zajac
Keyword(s):  
Muscle Activity ◽  
Isometric Force ◽  
Force Production ◽  
Rectus Femoris ◽  
Force Generation ◽  
Thigh Muscle ◽  
Work Output ◽  
Thigh Muscles ◽  
Sensorimotor Activity ◽  
Bifunctional Muscle

Locomotion requires uninterrupted transitions between limb extension and flexion. The role of contralateral sensorimotor signals in executing smooth transitions is little understood even though their participation is crucial to bipedal walking. However, elucidating neural interlimb coordinating mechanisms in human walking is difficult because changes to contralateral sensorimotor activity also affect the ipsilateral mechanics. Pedaling, conversely, is ideal for studying bilateral coordination because ipsilateral mechanics can be independently controlled. In pedaling, the anterior and posterior bifunctional thigh muscles develop needed anterior and posterior crank forces, respectively, to dominate the flexion-to-extension and extension-to-flexion transitions. We hypothesized that contralateral sensorimotor activity substantially contributes to the appropriate activation of these bifunctional muscles during the limb transitions. Bilateral pedal forces and surface electromyograms (EMGs) from four thigh muscles were collected from 15 subjects who pedaled with their right leg against a right-crank servomotor, which emulated the mechanical load experienced in conventional two-legged coupled-crank pedaling. In one pedaling session, the contralateral (left) leg pseudo-pedaled (i.e., EMG activity and pedal forces were pedaling-like, but pedal force was not allowed to affect crank rotation). In other sessions, the mechanically decoupled contralateral leg was first relaxed and then produced rhythmic isometric force trajectories during either leg flexion or one of the two limb transitions of the pedaling leg. With contralateral force production in the extension-to-flexion transition (predominantly by the hamstrings), rectus femoris activity and work output increased in the pedaling leg during its flexion-to-extension transition, which occurs simultaneously with contralateral extension-to-flexion in conventional pedaling. Similarly, with contralateral force production in the other transition (i.e., flexion-to-extension; predominantly by rectus femoris), hamstrings activity and work output increased in the pedaling leg during its extension-to-flexion transition. Therefore rhythmic isometric force generation in the contralateral leg supported the ongoing bifunctional muscle activity and resulting work output in the pedaling leg. The results suggest that neural interlimb coordinating mechanisms fine-tune bifunctional muscle activity in rhythmic lower-limb tasks to ensure limb flexion/extension transitions are executed successfully.

Posterior Thigh Muscle Injuries in Elite Track and Field Athletes

2010 ◽  
Vol 38 (9) ◽  
pp. 1813-1819 ◽  
Author(s):  
Nikolaos Malliaropoulos ◽  
Emmanuel Papacostas ◽  
Olga Kiritsi ◽  
PGD-MSK Rad ◽  
Agapi Papalada ◽  
...  
Keyword(s):  
Track And Field ◽  
Thigh Muscle ◽  
Muscle Injuries ◽  
Posterior Thigh

scholarly journals Is active sitting on a dynamic office chair controlled by the trunk muscles?

PLoS ONE ◽  
2020 ◽  
Vol 15 (11) ◽  
pp. e0242854
Author(s):  
Roman Peter Kuster ◽  
Christoph Michael Bauer ◽  
Daniel Baumgartner
Keyword(s):  
Muscle Activity ◽  
Muscle Activation ◽  
Positive Impact ◽  
Muscular Activity ◽  
Trunk Muscles ◽  
Thigh Muscle ◽  
Dominant Factor ◽  
Back Muscles ◽  
Temporal Muscle ◽  
Office Chair

Today’s office chairs are not known to promote active sitting or to activate the lumbar trunk muscles, both of which functions are ergonomically recommended. This study investigated a newly developed dynamic office chair with a moveable seat, specifically designed to promote trunk muscle controlled active sitting. The study aimed to determine the means by which the seat movement was controlled during active sitting. This was accomplished by quantifying trunk and thigh muscular activity and body kinematics. Additionally, the effect of increased spinal motion on muscular activity and body kinematics was analysed. Ten subjects were equipped with reflective body markers and surface electromyography on three lumbar back muscles (multifidus, iliocostalis, longissimus) and two thigh muscles (vastus lateralis and medialis). Subjects performed a reading task during static and active sitting in spontaneous and maximum ranges of motion in a simulated office laboratory setting. The temporal muscle activation pattern, average muscle activity and body segment kinematics were analysed and compared using Friedman and post-hoc Wilcoxon tests (p≤0.05). Active sitting on the new chair significantly affected the lumbar trunk muscles, with characteristic cyclic unloading/loading in response to the seat movement. Neither thigh muscle activity nor lateral body weight shift were substantially affected by active sitting. When participants increased their range of motion, the lumbar back muscles were activated for longer and relaxation times were shorter. The characteristic activity pattern of the lumbar trunk muscles was shown to be the most likely dominant factor in controlling seat movement during active sitting. Consequently, the new chair may have a potential positive impact on back health during prolonged sitting. Further studies are necessary to analyse the frequency and intensity of active sitting during daily office work.

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