scholarly journals Gastrocnemius fascicles are shorter and more pennate throughout the first month following acute Achilles tendon rupture

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6788 ◽  
Author(s):  
Todd J. Hullfish ◽  
Kathryn M. O’Connor ◽  
Josh R. Baxter
Keyword(s):  
Achilles Tendon ◽  
Muscle Thickness ◽  
Pennation Angle ◽  
Medial Gastrocnemius ◽  
Ultrasound Images ◽  
Echo Intensity ◽  
Post Injury ◽  
Fascicle Length ◽  
Clinical Visit ◽  
Tendon Ruptures

The purpose of this study was to characterize the short-term effects of Achilles tendon ruptures on medial gastrocnemius. We hypothesized that the fascicles of the medial gastrocnemius muscle of the injured Achilles tendon would be shorter and more pennate immediately following the injury and would persist throughout 4 weeks post-injury. B-mode longitudinal ultrasound images of the medial gastrocnemius were acquired in 10 adults who suffered acute Achilles tendon ruptures and were treated non-operatively. Ultrasound images were acquired during the initial clinical visit following injury as well as 2 and 4 weeks following this initial clinical visit. Resting muscle structure was characterized by measuring fascicle length, pennation angle, muscle thickness, and muscle echo intensity in both the injured and contralateral (control) limbs. Fascicle length was 15% shorter (P < 0.001) and pennation angle was 21% greater (P < 0.001) in the injured muscle compared to the uninjured (control) muscle at the presentation of injury (week 0). These differences in fascicle length persisted through 4 weeks after injury (P < 0.002) and pennation angle returned to pre-injury levels. Muscle thickness changes were not detected at any of the post-injury visits (difference < 4%, P > 0.026). Echo intensity of the injured limb was 8% lower at the presentation of the injury but was not different compared to the contralateral muscle at 2 and 4 weeks post-injury. Our results suggest that Achilles tendon ruptures elicit rapid changes in the configuration of the medial gastrocnemius, which may explain long-term functional deficits.

scholarly journals Gastrocnemius fascicles are shorter and more pennate throughout the first month following acute Achilles tendon rupture

2018 ◽  
Author(s):  
Todd J. Hullfish ◽  
Kathryn M O’Connor ◽  
Josh R. Baxter
Keyword(s):  
Achilles Tendon ◽  
Muscle Thickness ◽  
Pennation Angle ◽  
Medial Gastrocnemius ◽  
Ultrasound Images ◽  
Echo Intensity ◽  
Post Injury ◽  
Fascicle Length ◽  
Clinical Visit ◽  
Tendon Ruptures

AbstractThe purpose of this study was to characterize the short-term effects of Achilles tendon ruptures on medial gastrocnemius. We hypothesized that the fascicles of the medial gastrocnemius muscle of the injured Achilles tendon would be shorter and more pennate immediately following the injury and would persist throughout 4 weeks post-injury. B-mode longitudinal ultrasound images of the medial gastrocnemius were acquired in 10 adults who suffered acute Achilles tendon ruptures and were treated non-operatively. Ultrasound images were acquired during the initial clinical visit following injury as well as two and four weeks following this initial clinical visit. Resting muscle structure was characterized by measuring fascicle length, pennation angle, muscle thickness, and muscle echo intensity in both the injured and contralateral (control) limbs. Fascicle length was 15% shorter (P < 0.001) and pennation angle was 21% greater (P < 0.001) in the injured muscle compared to the uninjured (control) muscle at the presentation of injury (week 0). These differences in fascicle length and pennation angle persisted throughout the 4 weeks after the injury (P < 0.008). Muscle thickness changes were not detected at any of the post-injury visits (difference < 4%, P > 0.04). Echo intensity of the injured limb was 8% lower at the presentation of the injury and 11% lower (P = 0.008) than the contralateral muscle at 2 weeks following injury (P < 0.001) but returned to within 1% by 4 weeks (P = 0.393). Our results suggest that Achilles tendon ruptures elicit rapid changes in the configuration and quality of the medial gastrocnemius, which may explain long-term functional deficits.

scholarly journals Gastrocnemius Muscle Structure Remodels Within the First Month Following Acute Achilles Tendon Rupture

2019 ◽  
Vol 4 (4) ◽  
pp. 2473011419S0032
Author(s):  
Kathryn M O’Connor ◽  
Todd J. Hullfish ◽  
Josh R. Baxter
Keyword(s):  
Achilles Tendon ◽  
Gastrocnemius Muscle ◽  
Tendon Rupture ◽  
Achilles Tendon Rupture ◽  
Pennation Angle ◽  
Medial Gastrocnemius ◽  
Muscle Quality ◽  
Fascicle Length ◽  
Muscle Structure ◽  
Tendon Ruptures

Category: Sports, Trauma, Achilles Tendon Introduction/Purpose: Two out of three patients Achilles tendon ruptures have limited plantarflexor function 1-year following Achilles tendon rupture. While tendon elongation has been reported as a possible mechanism of functional deficits, the effects of rupture on plantarflexor muscle structure has not been as rigorously investigated. A recent study found that gastrocnemius fascicle length was decreased 6-months following Achilles tendon rupture compared to the uninjured limb. However, the changes in muscle structure following the first month of injury – when the healing tendon is most susceptible to elongation – has not yet been established. The purpose of this study was to quantify the structural changes to the medial gastrocnemius in patients who suffered acute Achilles tendon ruptures and were treated non-operatively. Methods: To test our hypothesis that plantarflexor structure would undergo rapid remodeling following Achilles tendon rupture, we quantified muscle structure in ten patients (9 male, Age: 44 ± 12; BMI: 28.6 ± 6.5) who provide informed written consent in this IRB approved study. We acquired B-mode ultrasound images of the medial gastrocnemius muscle at the initial presentation (week 0), two weeks, and four weeks following the injury. The same investigator acquired all the ultrasound images and measured fascicle length, pennation angle, muscle thickness, and echo intensity. These measurements had a coefficient of variation less than 10%. We compared these structural measurements of the injured muscle at each time point with the contralateral muscle scans at the initial presentation using paired t-tests. Results: Gastrocnemius muscle structure following an acute Achilles tendon rupture differed with the healthy-contralateral muscle throughout the first four weeks following injury (Figure). Fascicle length was 15% shorter (P < 0.001) and pennation angle was 21% greater (P < 0.001) at the presentation of injury (week 0). These differences in fascicle length (P < 0.001) and pennation angle persisted throughout the 4 weeks after the injury (P < 0.008). Muscle thickness changes were not detected at any of the post-injury visits. Muscle quality, measured as mean echo intensity, was 8% lower in the injured limb immediately (P= 0.008) and 11% lower 2 weeks following injury (P < 0.001). At week 4 muscle quality had returned to within 1% of the contralateral limb (P = 0.393). Conclusion: Our findings support our hypothesis that the gastrocnemius muscle fascicles of the affected side would demonstrate shorter length and greater pennation angle than the contralateral control muscle. These findings are a preliminary set of data from a larger clinical cohort of patients that were enrolled in an ongoing 1-year long prospective study. Achilles tendon ruptures elicit rapid changes in the configuration and quality of the medial gastrocnemius, which may explain long-term functional deficits.

scholarly journals Gastrocnemius muscle remodeling explains functional deficits three months following Achilles tendon rupture

2019 ◽  
Author(s):  
Todd J. Hullfish ◽  
Kathryn M. O’Connor ◽  
Josh R. Baxter
Keyword(s):  
Achilles Tendon ◽  
Gastrocnemius Muscle ◽  
Tendon Rupture ◽  
Achilles Tendon Rupture ◽  
Peak Torque ◽  
Pennation Angle ◽  
Medial Gastrocnemius ◽  
Fascicle Length ◽  
Functional Deficits ◽  
Muscle Remodeling

ABSTRACTPlantarflexor functional deficits are associated with poor outcomes in patients following Achilles tendon rupture. In this longitudinal study, we analyzed the fascicle length and pennation angle of the medial gastrocnemius muscle and the length of the Achilles tendon using ultrasound imaging. To determine the relationship between muscle remodeling and functional deficits measured at 3 months after injury, we correlated the reduction in fascicle length and increase in pennation angle with peak torque measured during isometric plantarflexor contractions and peak power measured during isokinetic plantarflexor contractions. We found that the medial gastrocnemius underwent an immediate change in structure, characterized by decreased length and increased pennation of the muscle fascicles. This decrease in fascicle length was coupled with an increase in tendon length. These changes in muscle-tendon structure persisted throughout the first three months following rupture. Deficits in peak plantarflexor power were moderately correlated with decreased fascicle length at 120 degrees per second (R2= 0.424,P= 0.057) and strongly correlated with decreased fascicle length at 210 degrees per second (R2= 0.737,P= 0.003). However, increases in pennation angle did not explain functional deficits. These findings suggest that muscle-tendon structure is detrimentally affected following Achilles tendon rupture. Plantarflexor power deficits are positively correlated with the magnitude of reductions in fascicle length. Preserving muscle structure following Achilles tendon rupture should be a clinical priority to maintain patient function.

Effects of the Functional Heel Drop Exercise on the Muscle Architecture of the Gastrocnemius

2020 ◽  
Vol 29 (8) ◽  
pp. 1053-1059
Author(s):  
Diego Alonso-Fernandez ◽  
Yaiza Taboada-Iglesias ◽  
Tania García-Remeseiro ◽  
Águeda Gutiérrez-Sánchez
Keyword(s):  
Repeated Measures ◽  
Muscle Thickness ◽  
Pennation Angle ◽  
Muscle Architecture ◽  
Medial Gastrocnemius ◽  
Control Group ◽  
Fascicle Length ◽  
Rehabilitation Programs ◽  
Architectural Characteristics ◽  
Induced Changes

Context: The architectural characteristics of a muscle determine its function. Objective: To determine the architectural adaptations of the lateral gastrocnemius (LG) and medial gastrocnemius (MG) muscles after a functional eccentric strength training protocol consisting of heel drop exercises, followed by a subsequent detraining period. Design: Pretest and posttest. Setting: Training rooms and laboratory. Participants: The participants (N = 45) who were randomly divided into an experimental group (EG, n = 25) and a control group (CG, n = 20). Interventions: The 13-week intervention included participants (N = 45) who were randomly divided into an EG (n = 25) and a CG (n = 20). The EG performed a week of control and training, 8 weeks of eccentric training, and 4 weeks of detraining. The CG did not perform any type of muscular training. The architectural characteristics of the LG and MG muscles were evaluated at rest in both groups using 2-D ultrasound before (pretest–week 1) and after (posttest–week 9) the training, and at the end of the detraining period (retest–week 13). Main Outcome Measures: One-way repeated measures analysis of variance was used to determine training-induced changes in each of the variables of the muscle architecture. Results: After the training period, the members of the EG experienced a significant increase in the fascicle length of LG (t = −9.85, d = 2.78, P < .001) and MG (t = −8.98, d = 2.54, P < .001), muscle thickness (t = −6.71, d = 2.86, P < .001) and (t = −7.85, d = 2.22, P < .001), and the pennation angle (t = −10.21, d = 1.88, P < .05) and (t = −1.87, d = 0.53, P < .05), respectively. After the detraining period, fascicle length, muscle thickness, and pennation angle showed a significant decrease. In the CG, no significant changes were observed in any of the variables. Conclusions: The heel drop exercise seems to generate adaptations in the architectural conditions of LG and MG, which are also reversible after a detraining period. These results may have practical implications for injury prevention and rehabilitation programs.

In vivo determination of fascicle curvature in contracting human skeletal muscles

2002 ◽  
Vol 92 (1) ◽  
pp. 129-134 ◽  
Author(s):  
Tadashi Muramatsu ◽  
Tetsuro Muraoka ◽  
Yasuo Kawakami ◽  
Akira Shibayama ◽  
Tetsuo Fukunaga
Keyword(s):  
Maximum Voluntary Contraction ◽  
Muscle Length ◽  
Muscle Thickness ◽  
Voluntary Contraction ◽  
Pennation Angle ◽  
Medial Gastrocnemius ◽  
Fascicle Length ◽  
Fascicle Curvature

Fascicle curvature of human medial gastrocnemius muscle (MG) was determined in vivo by ultrasonography during isometric contractions at three (distal, central, and proximal) locations ( n = 7) and at three ankle angles ( n = 7). The curvature significantly ( P < 0.05) increased from rest to maximum voluntary contraction (MVC) (0.4–5.2 m−1). In addition, the curvature at MVC became larger in the order dorsiflexed, neutral, plantar flexed ( P < 0.05). Thus both contraction levels and muscle length affected the curvature. Intramuscular differences in neither the curvature nor the fascicle length were found. The direction of curving was consistent along the muscle: fascicles were concave in the proximal side. Fascicle length estimated from the pennation angle and muscle thickness, under the assumption that the fascicle was straight, was underestimated by ∼6%. In addition, the curvature was significantly correlated to pennation angle and muscle thickness. These findings are particularly important for understanding the mechanical functions of human skeletal muscle in vivo.

Ultrasound analyses of hamstrings muscle morphology changes whit sport

2020 ◽  
Vol 30 (Supplement_2) ◽  
Author(s):  
R Santos ◽  
A Tavares
Keyword(s):  
Morphological Changes ◽  
Muscle Thickness ◽  
Pennation Angle ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Echo Intensity ◽  
Fascicle Length ◽  
Cross Sectional ◽  
Muscle Morphology ◽  
Ultrasound Parameters

Abstract Introduction Physical activities and sports can change muscle morphology. Changes caused by regular physical exercise can be assessed by ultrasound parameters such as the pennation angle, cross-sectional area, echo-intensity and muscle thickness. Objectives This study aims to characterise and evaluate the morphological changes of the hamstring muscles through ultrasound parameters such as the pennation angle, fascicle length, cross-sectional area, echo-intensity and muscle thickness, and verify the existence of morphological changes between the dominant and non-dominant limb. Methodology Twenty-two young female divided in two groups (control group=11; athletes group=11) were submitted to an ultrasound examination at 50% of the posterior region of the thigh, for the semimembranosus and long portion of the femoral biceps muscles in the longitudinal and in a panoramic view. Results 22 athletes with a mean age of 22.25 years were evaluated. There were significant differences between the two groups in muscle morphology. The athletes group showed a higher value for muscle thickness, cross-sectional area, pennation angle and fascicle length and a lower value for muscle echo-intensity. This group also showed higher values for these parameters when dominant limb is compared with non-dominant. Conclusion Physical exercise causes changes in muscle morphology and ultrasound is a good method for the musculoskeletal assessment of athlete’s performance, since it is an imaging modality that allows to carry out comparative bilateral studies for athletes performance follow up and for preventive strategies against the sedentarism.

scholarly journals Medial gastrocnemius muscle remodeling correlates with reduced plantarflexor kinetics 14 weeks following Achilles tendon rupture

2019 ◽  
Vol 127 (4) ◽  
pp. 1005-1011 ◽  
Author(s):  
Todd J. Hullfish ◽  
Kathryn M. O’Connor ◽  
Josh R. Baxter
Keyword(s):  
Achilles Tendon ◽  
Gastrocnemius Muscle ◽  
Tendon Rupture ◽  
Achilles Tendon Rupture ◽  
Peak Torque ◽  
Pennation Angle ◽  
Medial Gastrocnemius ◽  
Fascicle Length ◽  
Muscle Remodeling ◽  
Medial Gastrocnemius Muscle

Deficits in plantarflexor kinetics are associated with poor outcomes in patients following Achilles tendon rupture. In this longitudinal study, we analyzed the fascicle length and pennation angle of the medial gastrocnemius muscle and the length of the Achilles tendon using ultrasound imaging. To determine the relationship between muscle remodeling and deficits in plantarflexor kinetics measured at 14 wk after injury, we correlated the reduction in fascicle length and increase in pennation angle with peak torque measured during isometric and isokinetic plantarflexor contractions. We found that the medial gastrocnemius underwent an immediate change in structure, characterized by decreased length and increased pennation of the muscle fascicles. This decrease in fascicle length was coupled with an increase in tendon length. These changes in muscle-tendon structure persisted throughout the first 14 wk following rupture. Deficits in peak plantarflexor torque were moderately correlated with decreased fascicle length at 120 degrees per second ( R2 = 0.424, P = 0.057) and strongly correlated with decreased fascicle length at 210 degrees per second ( R2 = 0.737, P = 0.003). However, increases in pennation angle did not explain functional deficits. These findings suggest that muscle-tendon structure is detrimentally affected following Achilles tendon rupture. Plantarflexor power deficits are positively correlated with the magnitude of reductions in fascicle length. Preserving muscle structure following Achilles tendon rupture should be a clinical priority to maintain plantarflexor kinetics. NEW & NOTEWORTHY In our study, we found that when the Achilles tendon ruptures due to excessive biomechanical loading, the neighboring skeletal muscle undergoes rapid changes in its configuration. The magnitude of this muscle remodeling explains the amount of ankle power loss demonstrated by these patients once their Achilles tendons are fully healed. These findings highlight the interconnected relationship between muscle and tendon. Isolated injuries to the tendon stimulate detrimental changes to the muscle, thereby limiting joint-level function.

Semi-automated Tracing of Hamstring Muscle Architecture for B-mode Ultrasound Images

2021 ◽  
Author(s):  
Kevin Cronin ◽  
Eamonn Delahunt ◽  
Shane Foley ◽  
Giuseppe De Vito ◽  
Conor McCarthy ◽  
...  
Keyword(s):  
Muscle Thickness ◽  
Biceps Femoris ◽  
Pennation Angle ◽  
Ultrasound Images ◽  
Hamstring Muscle ◽  
Fascicle Length ◽  
Long Head ◽  
Architectural Characteristics ◽  
Biceps Femoris Long Head ◽  
Automated Tracing

AbstractHamstring strains are the most prevalent injury sustained by field-sport athletes. Insufficiencies in the architectural characteristics of the hamstring muscles can heighten an athlete’s risk of incurring a hamstring strain. To evaluate the influence of hamstring muscle architectural characteristics (i. e., fascicle length, pennation angle, muscle thickness) on injury risk, it is necessary to precisely evaluate these characteristics. Considering this, our aim was to develop and evaluate the precision of a novel semi-automated tracing software to measure the architectural characteristics of the biceps femoris long head (the most commonly injured hamstring muscle) in B-mode ultrasound images. We acquired static sonograms of the biceps femoris long head from ten healthy male field-sport athletes. The architectural characteristics (fascicle length, pennation angle, and muscle thickness) of participants’ biceps femoris long head were evaluated 10 times using the tracing software, with the specific purpose of determining its measurement precision. The tracing software precisely measured the architectural characteristics of the participants’ biceps femoris long head: fascicle length (% CV: 0.64–1.12), pennation angle (% CV: 2.58–10.70), muscle thickness (% CV: 0.48–2.04) Our semi-automated skeletal muscle tracing algorithm precisely measures fascicle length, pennation angles, and muscle thickness of the biceps femoris long head in static B-mode ultrasound images.

scholarly journals Muscle Thickness and Echo Intensity by Ultrasonography and Cognitive and Physical Dimensions in Older Adults

Diagnostics ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1471
Author(s):  
Alvaro Mateos-Angulo ◽  
Alejandro Galán-Mercant ◽  
Antonio Ignacio Cuesta-Vargas
Keyword(s):  
Older Adults ◽  
Older People ◽  
Physical Performance ◽  
Functional Capacity ◽  
Biceps Brachii ◽  
Handgrip Strength ◽  
Muscle Thickness ◽  
Medial Gastrocnemius ◽  
Echo Intensity ◽  
Physical Dimensions

The purpose of the present study was to investigate the associations between muscle thickness and echo intensity with cognitive and physical dimensions like functional capacity measured in older people. This cross-sectional study involved 20 older adults (15 women and 5 men, mean age ± SD: 85 ± 7 years, body mass index: 25 ± 3 kg/m2) from a geriatric centre in Malaga (Spain). Anthropometric measurements, cognitive assessment with Pfeiffer Short Portable Mental Status Questionnaire and Motor Memory test, Physical Performance with Short Physical Performance Battery, and muscle strength were tested. Additionally, using B-mode ultrasonography, images of wrist flexors, biceps brachii, rectus femoris, vastus lateralis, medial gastrocnemius, and tibialis anterior were captured, and muscle thickness and echo intensity variables were extracted. An association between muscle parameters assessed by ultrasonography and cognitive and physical dimensions were found in older people. Echo intensity was the best predictor in a set of regression models with different muscle parameters and a battery of cognitive and physical tests in older people. Echo intensity adjusted by handgrip strength could be a low cost and ambulatory index and an indirect and reversible indicator of functional capacity.

Comparison of Muscle Activity and Ultrasound Response of Lower Extremity Muscles During Treadmill and Track Running

2021 ◽  
Vol 11 (8) ◽  
pp. 2091-2096
Author(s):  
Chenghui Lin ◽  
Shudong Li ◽  
Yining Lu ◽  
Huw Wiltshire
Keyword(s):  
Lower Extremity ◽  
Muscle Thickness ◽  
Pennation Angle ◽  
Treadmill Running ◽  
Medial Gastrocnemius ◽  
Median Frequency ◽  
Muscle Morphology ◽  
Change Rate ◽  
Lower Extremity Muscle ◽  
Significant Difference

Purpose: The purpose of this study was to compare the changes in lower extremity muscle morphology and electromyography (EMG) signals during treadmill running (TR) and plastic track running (PR). Methods: A total of 10 healthy male runners aged 22.5±1.3 years, height: 175.5±4.5 cm; weight: 71.9±2.7 kg; BMI: 22.1±1.1 volunteered to participate in this study. Muscle morphology data were collected by a portable ultrasound scanner before and after running. Median frequency (MF), mean power frequency (MPF) and root mean square (RMS) were monitored during TR and PR. Results: The results indicated that muscle thickness and pennation angle have increased after running. The muscle thickness after PR showed significantly higher than TR in tested muscle except tibialis anterior (TA) and medial gastrocnemius (MG). In contrast, only the pennation angle of TA and lateral gastrocnemius (LG) after PR was significantly different from that after TR (P <0.001, P = 0.002). The most significant difference in the change rate of muscle thickness was found at TA. In addition, TA and MG showed significantly higher change rate of the pennation angle after TR than that after PR. Both of MF and MPF showed a downward trend after TR and PR. It could discover that the MF and MPF of LG during TR showed a significantly lower than that during PR both in two phases (P =0.001, P <0.001). However, in the last 5 minutes, MF and MPF of MQ during PR were smaller than that during PR (P = 0.001, P = 0.015). Furthermore, MF of RF during TR showed significantly different from that during PR (P = 0.017). From the point of RMS, in the first five minutes, the RMS of medical quadriceps (MQ), lateral quadriceps (LQ), hamstring muscles (HM) and MG during TR was significantly higher than that of PR (P <0.05). In addition, the RMS of all tested muscles after TR was significantly higher than after PR during the last 5 minutes (P <0.05). Conclusions: The current study indicated that TR and PR would cause different effects to lower extremity muscle morphology. In addition, the EMG signals based on running surfaces are also unconformity. Compared with the plastic track, the treadmill will bring more stimulation to the lower extremity muscles. The preliminary findings provide further insights into the rationality of runners’ choice of the running surface.

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