scholarly journals A functional MRI Exploration of Hamstring Activation During the Supine Bridge Exercise

2017 ◽  
Vol 39 (02) ◽  
pp. 104-109 ◽  
Author(s):  
Matthew Bourne ◽  
Morgan Williams ◽  
Tania Pizzari ◽  
Anthony Shield
Keyword(s):  
Muscle Activation ◽  
Biceps Femoris ◽  
Hamstring Injury ◽  
Clinical Test ◽  
Activation Patterns ◽  
Rehabilitation Programs ◽  
Intensity Changes ◽  
Long Head ◽  
Exercise Induced ◽  
Biceps Femoris Long Head

AbstractThe single leg supine bridge (SLB) is a commonly employed strengthening exercise and is used as a clinical test for hamstring function in sports, however, little is known about the patterns of muscle activation in this task. To explore these activation patterns, nine healthy, recreationally active males underwent functional magnetic resonance imaging (fMRI) of their thighs at rest and immediately after 5 sets of 10 repetitions of the SLB exercise. Exercise-induced increases in the transverse (T2) relaxation time of the biceps femoris long and short heads, semitendinosus and semimembranosus, were determined via signal intensity changes in pre- and post-exercise images and used as an index of muscle activation. The Bonferroni adjusted alpha was set at p<0.008. The semitendinosus exhibited a greater T2 increase than the biceps femoris short head (p<0.001, d=2.0) and semimembranosus (p=0.001, d=1.2), but not biceps femoris long head (p=0.029, d=0.9). Furthermore, the percentage change in T2 for biceps femoris long head was greater than its short head (p=0.003, d=1.4). During the SLB exercise, the semitendinosus is most selectively targeted and the biceps femoris long head is preferentially activated over its short head. These findings may have implications for the use of the SLB in hamstring injury prevention and rehabilitation programs.

Heterogeneous fascicle behavior within the biceps femoris long head at different muscle activation levels

2014 ◽  
Vol 47 (12) ◽  
pp. 3050-3055 ◽  
Author(s):  
Hunter J. Bennett ◽  
Patrick M. Rider ◽  
Zachary J. Domire ◽  
Paul DeVita ◽  
Anthony S. Kulas
Keyword(s):  
Muscle Activation ◽  
Biceps Femoris ◽  
Long Head ◽  
Biceps Femoris Long Head

scholarly journals Poor agreement between ultrasound and inbuilt diffusion tensor MRI measures of biceps femoris long head fascicle length

2018 ◽  
Vol 2 (2) ◽  
pp. 58-63 ◽  
Author(s):  
Fearghal P. Behan ◽  
Robin Vermeulen ◽  
Tessa Smith ◽  
Javier Arnaiz ◽  
Rodney Whiteley ◽  
...  
Keyword(s):  
Diffusion Tensor ◽  
Biceps Femoris ◽  
Diffusion Tensor Mri ◽  
Poor Agreement ◽  
Fascicle Length ◽  
Long Head ◽  
Biceps Femoris Long Head

Difference of Hamstring Activity Between Bilateral and Unilateral Nordic Hamstring Exercises With a Sloped Platform

2021 ◽  
pp. 1-6
Author(s):  
Toshiaki Soga ◽  
Taspol Keerasomboon ◽  
Kei Akiyama ◽  
Norikazu Hirose
Keyword(s):  
High Speed ◽  
Biceps Femoris ◽  
Break Point ◽  
Hamstring Injury ◽  
Emg Activity ◽  
Maximum Voluntary Isometric Contraction ◽  
Mean Values ◽  
Significant Difference ◽  
Long Head ◽  
Control Study

Context: This study aimed to examine the differences in electromyographic (EMG) activity of the biceps femoris long head (BFlh) and semitendinosus (ST) muscles, break-point angle (BPA), and the angle at peak BFlh EMG activity between bilateral and unilateral Nordic hamstring exercise (NHE) on a sloped platform. Design: This study was designed as a case-control study. Methods: Fourteen men participated in the study. The participants initially performed maximum voluntary isometric contraction (MVIC) on the prone leg curl to normalize the peak hamstring EMG amplitude as the %MVIC. Then, participants were randomized to perform the following 3 variations of NHE: bilateral (N40) or unilateral (N40U) NHE with a platform angle of 40°, and unilateral NHE with a platform angle of 50° (N50U). The EMG activities of the BFlh and ST and the knee flexion angle during the NHE variations were recorded to calculate the EMG activity of the BFlh and ST in terms of the %MVIC, the angle at peak BFlh EMG, and BPA. Results: The BFlh %MVIC was significantly higher in N40U (P < .05) and N50U (P < .05) than in N40. A significant difference in BFlh %MVIC and ST %MVIC was observed between N40U (P < .05) and N50U (P < .05). The mean values of BPA and the angle at peak BFlh EMG were <30° for all NHE variations. Conclusions: In the late swing phase of high-speed running, BFlh showed higher EMG activity; thus, unilateral NHE may be a specific hamstring exercise for hamstring injury prevention.

Muscle- and Region-Specific Associations Between Muscle Size and Muscular Strength During Hip Extension and Knee Flexion in the Hamstrings

2021 ◽  
pp. 1-6
Author(s):  
Raki Kawama ◽  
Masamichi Okudaira ◽  
Hirohiko Maemura ◽  
Satoru Tanigawa
Keyword(s):  
Knee Flexion ◽  
Muscular Strength ◽  
Sports Injuries ◽  
Biceps Femoris ◽  
Muscle Size ◽  
Cross Sectional ◽  
Long Head ◽  
Hip Extension ◽  
Flexion Strength ◽  
Biceps Femoris Long Head

Context: Strength deficits of the hamstrings following sports injuries decrease athletic performance and increase the risk of injury recurrence. Previous studies have shown a high correlation between the muscular strength during hip-extension and knee-flexion and total muscle size of the hamstrings. However, it remains unclear which region of the individual hamstring muscles is closely associated with muscular strength. Objective: To investigate the relationship between the size of each region of the individual hamstring muscles and muscular strength during hip extension and knee flexion. Design: Within-subject repeated measures. Setting: University laboratory. Participants: Twenty healthy young male volunteers who regularly engaged in sports activities. Outcome Measures: Anatomical cross-sectional areas were acquired from the proximal, middle, and distal regions of the biceps femoris long head, biceps femoris short head, semitendinosus, and semimembranosus. Hip-extension and knee-flexion strength were measured during maximal voluntary isometric and concentric contractions (angular velocities of 60°/s and 180°/s). Results: The anatomical cross-sectional area of the distal regions in biceps femoris long head (r = .525–.642) and semitendinosus (r = .567) were significantly correlated with hip-extension strength under all conditions and only at an angular velocity of 180°/s, respectively. Meanwhile, anatomical cross-sectional areas of the distal regions in biceps femoris short head (r = .587–.684) and semimembranosus (r = .569–.576) were closely associated with knee-flexion strength under all conditions. Conclusion: These results suggest that muscle size in the distal regions of biceps femoris long head and semitendinosus greatly contributes to the production of hip-extension strength, whereas that of biceps femoris short head and semimembranosus significantly contributes to the generation of knee-flexion strength. These findings could be useful for designing training and rehabilitation programs to efficiently improve strength deficits following sports injuries such as strain injury and anterior cruciate ligament tears.

Biceps femoris long head muscle fascicle length does not differ between sexes

2019 ◽  
Vol 37 (21) ◽  
pp. 2452-2458
Author(s):  
Fearghal P. Behan ◽  
Rachael Moody ◽  
Tejal Sarika Patel ◽  
Edward Lattimore ◽  
Thomas M. Maden-Wilkinson ◽  
...  
Keyword(s):  
Biceps Femoris ◽  
Fascicle Length ◽  
Muscle Fascicle ◽  
Long Head ◽  
Biceps Femoris Long Head

scholarly journals MR biomarkers predict clinical function in Duchenne muscular dystrophy

Neurology ◽  
2020 ◽  
Vol 94 (9) ◽  
pp. e897-e909 ◽  
Author(s):  
Alison M. Barnard ◽  
Rebecca J. Willcocks ◽  
William T. Triplett ◽  
Sean C. Forbes ◽  
Michael J. Daniels ◽  
...  
Keyword(s):  
Duchenne Muscular Dystrophy ◽  
Muscular Dystrophy ◽  
Lower Extremity ◽  
Vastus Lateralis ◽  
Strong Relationship ◽  
Biceps Femoris ◽  
Loss Of Function ◽  
Long Head ◽  
Biceps Femoris Long Head ◽  
Over Time

ObjectiveTo investigate the potential of lower extremity magnetic resonance (MR) biomarkers to serve as endpoints in clinical trials of therapeutics for Duchenne muscular dystrophy (DMD) by characterizing the longitudinal progression of MR biomarkers over 48 months and assessing their relationship to changes in ambulatory clinical function.MethodsOne hundred sixty participants with DMD were enrolled in this longitudinal, natural history study and underwent MR data acquisition of the lower extremity muscles to determine muscle fat fraction (FF) and MRI T2 biomarkers of disease progression. In addition, 4 tests of ambulatory function were performed. Participants returned for follow-up data collection at 12, 24, 36, and 48 months.ResultsLongitudinal analysis of the MR biomarkers revealed that vastus lateralis FF, vastus lateralis MRI T2, and biceps femoris long head MRI T2 biomarkers were the fastest progressing biomarkers over time in this primarily ambulatory cohort. Biomarker values tended to demonstrate a nonlinear, sigmoidal trajectory over time. The lower extremity biomarkers predicted functional performance 12 and 24 months later, and the magnitude of change in an MR biomarker over time was related to the magnitude of change in function. Vastus lateralis FF, soleus FF, vastus lateralis MRI T2, and biceps femoris long head MRI T2 were the strongest predictors of future loss of function, including loss of ambulation.ConclusionsThis study supports the strong relationship between lower extremity MR biomarkers and measures of clinical function, as well as the ability of MR biomarkers, particularly those from proximal muscles, to predict future ambulatory function and important clinical milestones.ClinicalTrials.gov identifierNCT01484678.

Hamstring Eccentric Strengthening Program: Does Training Volume Matter?

2020 ◽  
Vol 15 (1) ◽  
pp. 81-90 ◽  
Author(s):  
Mathieu Lacome ◽  
Simon Avrillon ◽  
Yannick Cholley ◽  
Ben M. Simpson ◽  
Gael Guilhem ◽  
...  
Keyword(s):  
Biceps Femoris ◽  
High Volume ◽  
Soccer Players ◽  
Eccentric Training ◽  
Fascicle Length ◽  
Knee Flexor ◽  
Low Volume ◽  
Long Head ◽  
Biceps Femoris Long Head ◽  
Flexor Strength

Aim: To compare the effect of low versus high volume of eccentric-biased hamstring training programs on knee-flexor strength and fascicle length changes in elite soccer players. Methods: A total of 19 elite youth soccer players took part in this study and were randomly assigned into 2 subgroups. For 6 weeks in-season, the groups performed either a low-volume (1 set per exercise; 10 repetitions in total) or a high-volume (4 sets; 40 repetitions) eccentric training of their knee flexors. After 6-weeks midtraining (MID), players performed the alternate training regimen. Each training set consisted of 4 repetitions of the Nordic hamstring exercise and 6 repetitions of the bilateral stiff-leg deadlift. Eccentric knee-flexor strength (NordBord) as well as biceps femoris long head and semimembranosus fascicle length (scanned with ultrasound scanner) were assessed during pretraining (PRE), MID, and posttraining (POST) tests. Results: Knee-flexor eccentric strength very likely increased from PRE to MID (low volume: +11.3% [7.8%] and high volume: 11.4% [5.3%]), with a possibly-to-likely increase in biceps femoris long head (+4.5% [5.0%] and 4.8% [2.5%]) and semimembranosus (+4.3% [4.7%] and 6.3% [6.3%]) fascicle length in both groups. There was no substantial changes between MID and POST. Overall, there was no clear between-group difference in the changes from PRE to MID and MID to POST for neither knee-flexor eccentric strength, biceps femoris long head, nor semimembranosus fascicle length. Conclusions: Low-volume knee-flexor eccentric training is as effective as a greater training dose to substantially improve knee-flexor strength and fascicle length in-season in young elite soccer players. Low volume is, however, likely more appropriate to be used in an elite team facing congested schedules.

Is Biceps Femoris Aponeurosis Size an Independent Risk Factor for Strain Injury?

2020 ◽  
Vol 41 (08) ◽  
pp. 552-557 ◽  
Author(s):  
Sandro R. Freitas ◽  
Filipe Abrantes ◽  
Francisco Santos ◽  
Vasco Mascarenhas ◽  
Raúl Oliveira ◽  
...  
Keyword(s):  
Risk Factor ◽  
Independent Risk Factor ◽  
Biceps Femoris ◽  
Isometric Strength ◽  
Resonance Imaging ◽  
Injured Limb ◽  
Previous Injury ◽  
Knee Flexor ◽  
Long Head ◽  
Biceps Femoris Long Head

AbstractThis study examined whether professional footballers with previous biceps femoris long head (BFLH) injury in the last 3-years present a smaller proximal aponeurosis (Apo-BFLH) size compared to footballers with no previous injury. We examined the Apo-BFLH and BFLH size using magnetic resonance imaging and tested the knee flexor maximal isometric strength in 80 thighs of 40 footballers. Apo-BFLH size parameters were processed using a semi-automated procedure. Outcomes were compared between thighs with (n=9) vs. without (n=71) previous BFLH injury. No differences were observed between injured and non-injured thighs for the Apo-BFLH and BFLH size parameters (p>0.05) except for Apo-BFLH volume, which was higher in the non-injured thighs of athletes with previous injury (3692.1±2638.4 mm3, p<0.006) compared to the left (2274.1±798.7 mm3) thighs of athletes without previous injury. A higher knee flexor isometric strength was observed in the injured limb of athletes with previous BFLH injury (196.5±31.9 Nm, p<0.003) compared to the left (156.2±31.4 Nm) and right (160.0±31.4 Nm) thighs of non-injured athletes. The present results suggest that BFLH proximal aponeurosis size should not be considered as an independent risk factor for strain injury.

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