scholarly journals An automatic fascicle tracking algorithm quantifying gastrocnemius architecture during maximal effort contractions

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7120 ◽  
Author(s):  
John F. Drazan ◽  
Todd J. Hullfish ◽  
Josh R. Baxter
Keyword(s):  
Pennation Angle ◽  
Tracking Algorithm ◽  
Medial Gastrocnemius ◽  
Fascicle Length ◽  
Automatic Tracking ◽  
Individual Muscle ◽  
Muscle Fascicle ◽  
Muscle Fascicles ◽  
Maximal Effort ◽  
Strong Agreement

Background Ultrasound has become a commonly used imaging modality for making dynamic measurements of muscle structure during functional movements in biomechanical studies. Manual measurements of fascicle length and pennation angle are time intensive which limits the clinical utility of this approach while also limiting sample sizes in research. The purpose of this study was to develop an automatic fascicle tracking program to quantify the length and pennation angle of a muscle fascicle during maximal effort voluntary contractions and to evaluate its repeatability between days and reproducibility between different examiners. Methods Five healthy adults performed maximal effort isometric and isokinetic contractions at 30, 120, 210, and 500 degrees per second about their ankle on an isokinetic dynamometer while their medial gastrocnemius muscle was observed using ultrasound. Individual muscle fascicles and the two aponeuroses were identified by the user in the first frame and automatically tracked by the algorithm by three observers on three separate days. Users also made manual measurements of the candidate fascicle for validation. Repeatability within examiners across days and reproducibility across examiners and days were evaluated using intra-class correlation coefficients (ICC). Agreement between manual and automatic tracking was evaluated using the coefficient of multiple correlations (CMC) and root-mean-square error. Supervised automatic tracking, where the program could be reinitialized if poor tracking was observed, was performed on all videos by one examiner to evaluate the performance of automatic tracking in a typical use case. We also compared the performance our program to a preexisting automatic tracking program. Results We found both manual and automatic measurements of fascicle length and pennation angle to be strongly repeatable within examiners and strongly reproducible across examiners and days (ICCs > 0.74). There was greater agreement between manual and automatic measurements of fascicle length than pennation angle, however the mean CMC value was found to be strong in both cases (CMC > 0.8). Supervision of automatic tracking showed very strong agreement between manual and automatic measurements of fascicle length and pennation angle (CMC > 0.94). It also had considerably less error relative to the preexisting automatic tracking program. Conclusions We have developed a novel automatic fascicle tracking algorithm that quantifies fascicle length and pennation angle of individual muscle fascicles during dynamic contractions during isometric and across a range of isokinetic velocities. We demonstrated that this fascicle tracking algorithm is strongly repeatable and reproducible across different examiners and different days and showed strong agreement with manual measurements, especially when tracking is supervised by the user so that tracking can be reinitialized if poor tracking quality is observed.

scholarly journals An automatic fascicle tracking algorithm quantifying gastrocnemius architecture during maximal effort contractions

2019 ◽  
Author(s):  
John F Drazan ◽  
Todd J Hullfish ◽  
Josh R Baxter
Keyword(s):  
Intraclass Correlation ◽  
Correlation Coefficients ◽  
Pennation Angle ◽  
Tracking Algorithm ◽  
Fascicle Length ◽  
Automatic Tracking ◽  
Individual Muscle ◽  
Isokinetic Contractions ◽  
Muscle Fascicles ◽  
Strong Agreement

Background. Ultrasound has become the gold-standard for making dynamic measurements of muscle structure during functional movements in biomechanical studies. Manual measurements of fascicle length and pennation angle are time intensive which limits the clinical utility of this approach while also limiting sample sizes. The purpose of this study was to develop a novel tracking paradigm to quantify individual fascicle length and pennation measurements during maximal voluntary contractions and demonstrate is repeatability between days and reproducibility between different examiners. Methods. Five healthy young adults performed maximal isokinetic contractions at 0, 30, 120, 210, and 500 degrees about their ankle on an isokinetic dynamometer while their gastrocnemius muscle was observed using ultrasound. Individual muscle fascicles were identified in the first frame, and tracked using the automatic fascicle tracking algorithm and a manual approach by three observers on three separate days. Repeatability within examiners across days and reproducibility across examiners and days was evaluated using intraclass correlation coefficients. Agreement between manual and automatic tracking was evaluated using the coefficient of multiple correlations. Supervised automatic tracking was performed on all videos by one examiner to evaluate the fidelity of automatic tracking in practice. Results. We found both manual and automatic measurements of fascicle length and pennation angle to be strongly repeatable within examiners and strongly reproducible across examiners and days (ICCs>0.76). There was greater agreement between manual and automatic measurements of fascicle length than pennation angle, however the mean CMC value for both was still found to be strong in both cases (CMC>0.8). Supervision of automatic tracking greatly showed very strong agreement between manual and automatic measurements of fascicle length and pennation angle (CMC>0.94). Conclusions. We have developed a novel automatic fascicle tracking algorithm that quantifies fascicle length and pennation angle of individual muscle fascicles during dynamic contractions across a range of velocities. We demonstrated that this fascicle tracking algorithm is repeatable and reproducible across different examiners and different days and showed strong agreement with manual measurements, especially when tracking is supervised by the user so that tracking can be reinitialized if poor tracking fidelity is observed.

scholarly journals An automatic fascicle tracking algorithm quantifying gastrocnemius architecture during maximal effort contractions

2019 ◽  
Author(s):  
John F Drazan ◽  
Todd J Hullfish ◽  
Josh R Baxter
Keyword(s):  
Intraclass Correlation ◽  
Correlation Coefficients ◽  
Pennation Angle ◽  
Tracking Algorithm ◽  
Fascicle Length ◽  
Automatic Tracking ◽  
Individual Muscle ◽  
Isokinetic Contractions ◽  
Muscle Fascicles ◽  
Strong Agreement

Background. Ultrasound has become the gold-standard for making dynamic measurements of muscle structure during functional movements in biomechanical studies. Manual measurements of fascicle length and pennation angle are time intensive which limits the clinical utility of this approach while also limiting sample sizes. The purpose of this study was to develop a novel tracking paradigm to quantify individual fascicle length and pennation measurements during maximal voluntary contractions and demonstrate is repeatability between days and reproducibility between different examiners. Methods. Five healthy young adults performed maximal isokinetic contractions at 0, 30, 120, 210, and 500 degrees about their ankle on an isokinetic dynamometer while their gastrocnemius muscle was observed using ultrasound. Individual muscle fascicles were identified in the first frame, and tracked using the automatic fascicle tracking algorithm and a manual approach by three observers on three separate days. Repeatability within examiners across days and reproducibility across examiners and days was evaluated using intraclass correlation coefficients. Agreement between manual and automatic tracking was evaluated using the coefficient of multiple correlations. Supervised automatic tracking was performed on all videos by one examiner to evaluate the fidelity of automatic tracking in practice. Results. We found both manual and automatic measurements of fascicle length and pennation angle to be strongly repeatable within examiners and strongly reproducible across examiners and days (ICCs>0.76). There was greater agreement between manual and automatic measurements of fascicle length than pennation angle, however the mean CMC value for both was still found to be strong in both cases (CMC>0.8). Supervision of automatic tracking greatly showed very strong agreement between manual and automatic measurements of fascicle length and pennation angle (CMC>0.94). Conclusions. We have developed a novel automatic fascicle tracking algorithm that quantifies fascicle length and pennation angle of individual muscle fascicles during dynamic contractions across a range of velocities. We demonstrated that this fascicle tracking algorithm is repeatable and reproducible across different examiners and different days and showed strong agreement with manual measurements, especially when tracking is supervised by the user so that tracking can be reinitialized if poor tracking fidelity is observed.

scholarly journals Differences in Plantar Flexor Fascicle Length and Pennation Angle between Healthy and Poststroke Individuals and Implications for Poststroke Plantar Flexor Force Contributions

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
John W. Ramsay ◽  
Thomas S. Buchanan ◽  
Jill S. Higginson
Keyword(s):  
Pennation Angle ◽  
Medial Gastrocnemius ◽  
Plantar Flexor ◽  
Flexor Muscle ◽  
Fascicle Length ◽  
Cross Sectional ◽  
Lateral Gastrocnemius ◽  
Relative Contribution ◽  
Muscle Fascicle ◽  
The Individual

Poststroke plantar flexor muscle weakness has been attributed to muscle atrophy and impaired activation, which cannot collectively explain the limitations in force-generating capability of the entire muscle group. It is of interest whether changes in poststroke plantar flexor muscle fascicle length and pennation angle influence the individual force-generating capability and whether plantar flexor weakness is due to uniform changes in individual muscle force contributions. Fascicle lengths and pennation angles for the soleus, medial, and lateral gastrocnemius were measured using ultrasound and compared between ten hemiparetic poststroke subjects and ten healthy controls. Physiological cross-sectional areas and force contributions to poststroke plantar flexor torque were estimated for each muscle. No statistical differences were observed for any muscle fascicle lengths or for the lateral gastrocnemius and soleus pennation angles between paretic, nonparetic, and healthy limbs. There was a significant decrease (P<0.05) in the paretic medial gastrocnemius pennation angle compared to both nonparetic and healthy limbs. Physiological cross-sectional areas and force contributions were smaller on the paretic side. Additionally, bilateral muscle contributions to plantar flexor torque remained the same. While the architecture of each individual plantar flexor muscle is affected differently after stroke, the relative contribution of each muscle remains the same.

scholarly journals Gastrocnemius muscle fascicle behavior during stair negotiation in humans

2007 ◽  
Vol 102 (4) ◽  
pp. 1618-1623 ◽  
Author(s):  
M. Spanjaard ◽  
N. D. Reeves ◽  
J. H. van Dieën ◽  
V. Baltzopoulos ◽  
C. N. Maganaris
Keyword(s):  
Joint Kinematics ◽  
Lower Limbs ◽  
Medial Gastrocnemius ◽  
Fascicle Length ◽  
Stair Ascent ◽  
Muscle Fascicle ◽  
Stair Negotiation ◽  
Knee Joint Kinematics ◽  
Length Changes ◽  
Muscle Fascicles

The aim of the present study was to establish the behavior of human medial gastrocnemius (GM) muscle fascicles during stair negotiation. Ten healthy male subjects performed normal stair ascent and descent at their own comfortable speed on a standard-dimension four-step staircase with embedded force platforms in each step. Kinematic, kinetic, and electromyographic data of the lower limbs were collected. Real-time ultrasound scanning was used to determine GM muscle fascicle length changes. Musculotendon complex (MTC) length changes were estimated from ankle and knee joint kinematics. The GM muscle was mainly active during the push-off phase in stair ascent, and the muscle fascicles contracted nearly isometrically. The GM muscle was mainly active during the touch-down phase of stair descent where the MTC was lengthened; however, the GM muscle fascicles shortened by ∼7 mm. These findings show that the behavior and function of GM muscle fascicles in stair negotiation is different from that expected on the basis of length changes of the MTC as derived from joint kinematics.

Plantar Flexor Muscle Architecture Changes as a Result of Eccentric Exercise in Patients With Achilles Tendinosis

2014 ◽  
Vol 7 (6) ◽  
pp. 460-465 ◽  
Author(s):  
Matthew T. Crill ◽  
Gregory Berlet ◽  
Christopher Hyer
Keyword(s):  
Case Series ◽  
Muscle Architecture ◽  
Medial Gastrocnemius ◽  
Eccentric Training ◽  
Plantar Flexors ◽  
Flexor Muscle ◽  
Fascicle Length ◽  
Achilles Tendinosis ◽  
Muscle Fascicle ◽  
Maximal Load

Eccentric training for Achilles tendinosis (AT) has been reported to significantly improve patient symptoms. There has been no biomechanical explanation on the mechanism for specific rehabilitation technique. The purpose of this study was to determine changes in muscle architecture that occurred as a result of Achilles tendinosis injury and a subsequent eccentric rehabilitation program. Twenty-five patients (age, 53.3 ± 17.5 years) diagnosed with AT participated in 6 weeks of rehabilitation. Specific exercises for the ankle plantar flexors consisted of maximal load eccentric muscle action using 3 sets of 15 repetitions. Patients also completed a protocol for AT, which consisting of traditional rehabilitation. Medial gastrocnemius (GM) and lateral gastrocnemius (GL) muscle fascicle length and thickness were measured with ultrasound at 2-week intervals from initial treatment day to the end of 6 weeks of rehabilitation. Medial gastrocnemius fascicle length increased (45.1 ± 10.5 mm to 51.4 ± 10.5 mm; P = .22) between the initial day of rehabilitation and after 6 weeks of rehabilitation. But, GM thickness (16.3 ± 3.5 mm to 16.8 ± 2.0 mm), GL fascicle length (47.2 ± 10.0 mm to 47.1 ± 7.4 mm), and GL thickness (14.9 ± 5.2 mm to 14.4 ± 2.7 mm) did not change as a result of rehabilitation. A 6-week eccentric-biased exercise increased the GM muscle fascicle length by 12%, but GM thickness, GL fascicle length, and GL thickness did not change as a result of rehabilitation. Eccentric training for the treatment of AT is well recognized, but the mechanism of action has not been previously reported. A 6-week eccentric training protocol increased the GM muscle fascicle length by 12%, and this correlated with improvement in a validated patient outcome scoring system. Further study is warranted to determine a predictive relationship between improvement of GM fascicle length and outcome scores. Levels of Evidence: Therapeutic, Level IV: Case series

scholarly journals Ultrasound Structural Changes in Triceps Surae After a 1-Year Daily Self-stretch Program: A Prospective Randomized Controlled Trial in Chronic Hemiparesis

2019 ◽  
Vol 33 (4) ◽  
pp. 245-259 ◽  
Author(s):  
Maud Pradines ◽  
Mouna Ghedira ◽  
Raphaël Portero ◽  
Ingrid Masson ◽  
Christina Marciniak ◽  
...  
Keyword(s):  
Structural Changes ◽  
Controlled Trial ◽  
Triceps Surae ◽  
Medial Gastrocnemius ◽  
Plantar Flexors ◽  
Fascicle Length ◽  
Rehabilitation Programs ◽  
Lower Limb Muscles ◽  
Muscle Fascicle ◽  
Prospective Randomized Controlled Trial

Introduction. The effects of long-term stretching (>6 months) in hemiparesis are unknown. This prospective, randomized, single-blind controlled trial compared changes in architectural and clinical parameters in plantar flexors of individuals with chronic hemiparesis following a 1-year guided self-stretch program, compared with conventional rehabilitation alone. Methods. Adults with chronic stroke-induced hemiparesis (time since lesion >1 year) were randomized into 1 of 2, 1-year rehabilitation programs: conventional therapy (CONV) supplemented with the Guided Self-rehabilitation Contract (GSC) program, or CONV alone. In the GSC group, specific lower limb muscles, including plantar flexors, were identified for a diary-based treatment utilizing daily, high-load, home self-stretching. Blinded assessments included (1) ultrasonographic measurements of soleus and medial gastrocnemius (MG) fascicle length and thickness, with change in soleus fascicle length as primary outcome; (2) maximum passive muscle extensibility (XV1, Tardieu Scale); (3) 10-m maximal barefoot ambulation speed. Results. In all, 23 individuals (10 women; mean age [SD], 56 [±12] years; time since lesion, 9 [±8] years) were randomized into either the CONV (n = 11) or GSC (n = 12) group. After 1 year, all significant between-group differences favored the GSC group: soleus fascicle length, +18.1mm [9.3; 29.9]; MG fascicle length, +6.3mm [3.5; 9.1]; soleus thickness, +4.8mm [3.0; 7.7]; XV1 soleus, +4.1° [3.1; 7.2]; XV1 gastrocnemius, +7.0° [2.1; 11.9]; and ambulation speed, +0.07m/s [+0.02; +0.16]. Conclusions. In chronic hemiparesis, daily self-stretch of the soleus and gastrocnemius over 1 year using GSC combined with conventional rehabilitation increased muscle fascicle length, extensibility, and ambulation speed more than conventional rehabilitation alone.

M-wave potentiation after voluntary contractions of different durations and intensities in the tibialis anterior

2015 ◽  
Vol 118 (8) ◽  
pp. 953-964 ◽  
Author(s):  
Javier Rodriguez-Falces ◽  
Jacques Duchateau ◽  
Yoshiho Muraoka ◽  
Stéphane Baudry
Keyword(s):  
Tibialis Anterior ◽  
Compound Action Potential ◽  
Pennation Angle ◽  
Second Phase ◽  
Median Frequency ◽  
Fascicle Length ◽  
M Wave ◽  
Muscle Fascicle ◽  
Phase Amplitude ◽  
Voluntary Contractions

The study was undertaken to provide insight into the mechanisms underlying the potentiation of the muscle compound action potential (M wave) after conditioning contractions. M waves were evoked in the tibialis anterior before and after isometric maximal voluntary contractions (MVC) of 1, 3, 6, 10, 30, and 60 s, and after 3-s contractions at 10, 30, 50, 70, 90, and 100% MVC. The amplitude, duration, and area of the first and second phases of the M wave, together with the median frequency (Fmedian) and muscle fiber conduction velocity (MFCV) were recorded. Furthermore, twitch force, muscle fascicle length, and pennation angle were measured at rest, before, and 1 s after the conditioning contractions. The results indicate that only the amplitude of the second phase of the M wave was significantly increased after conditioning contractions. The extent of this potentiation was similar for MVC durations ranging from 1 to 10 s and augmented progressively with contraction intensity from 30 to 70% MVC. After these conditioning contractions, the duration and area of the two M-wave phases decreased ( P < 0.05), whereas MFCV and Fmedian increased ( P < 0.05). For all of these parameters, the greatest changes occurred 1 s after the conditioning contraction. Changes in MFCV after the contractions were correlated with those in M-wave second-phase amplitude ( r2 = 0.42; P < 0.05) and Fmedian ( r2 = 0.53; P < 0.05). In contrast, fascicle length and pennation angle did not change after the conditioning contractions. It is concluded that the potentiation of the second phase of the M wave is mainly due to an increased MFCV.

scholarly journals Differences in Gastrocnemius Muscle Architectural Properties between Child Female Athletes with Different Flexibility Training Backgrounds

Proceedings ◽  
2019 ◽  
Vol 25 (1) ◽  
pp. 11
Author(s):  
Panidi ◽  
Bogdanis ◽  
Gaspari ◽  
Spiliopoulou ◽  
Donti ◽  
...  
Keyword(s):  
Repeated Measures ◽  
Distal Part ◽  
Muscle Thickness ◽  
Pennation Angle ◽  
Static Stretching ◽  
Fascicle Length ◽  
Muscle Fascicle ◽  
Flexibility Training ◽  
Architectural Characteristics ◽  
Rhythmic Gymnasts

AIM: Τhe mechanisms underpinning long-term changes in muscle architectural characteristics and joint range of motion (ROM) following static stretching in humans remain under question, and data are sparse for growing athletes. It is possible that the characteristics of the stretching protocols used in previous training studies were not adequate to induce significant changes. An alternative approach would be to compare populations with different chronic flexibility training backgrounds. Thus, the purpose of this study was to examine differences in gastrocnemius medialis (GM) architectural characteristics at rest and during 1 min of static stretching between child athletes with different flexibility training backgrounds. MATERIAL & METHOD: Ten female rhythmic gymnasts (RG; age. 9.0 ± 0.7 years) were compared to six volleyball athletes (VA; age, 9.0 ± 0.6 years). Fascicle length, pennation angle and muscle thickness at the medial and distal part of GM, and ankle ROM were measured at rest and during 1 min of static stretching using ultrasonography. Data were analysed using two-way ANOVA for repeated measures on two factors (time x sport). RESULTS: At rest, RG displayed similar fascicle length compared to VA at the medial (4.19 ± 0.37 vs. 4.24 ± 0.54 cm, respectively, p = 0.841) and the distal part of GM (4.25 ± 0.35 vs. 4.18 ± 0.65 cm, respectively, p = 0.780). Pennation angle and muscle thickness were also similar in the two groups at the medial (p = 0.519 and p = 0.216, respectively) and the distal part of the gastrocnemius (p = 0.998 and p = 0.433, respectively). Ankle angle before stretching was greater in RG compared with VA (120.9 ± 4.2 vs. 110.9 ± 5.8°, respectively, p = 0.001). During the 1 min of static stretching, RG displayed greater fascicle elongation compared to the VA at the medial (5.86 ± 0.29 vs 5.52 ± 0.53 cm, p = 0.048) and the distal part (6.09 ± 0.49 vs 5.15 ± 0.65 cm, p = 0.013), as well as greater maximal ankle dorsiflexion (p < 0.001) and muscle tendon junction displacement (p < 0.001). No differences were found between groups in pennation angle (p > 0.458) and muscle thickness (p ˃ 0.237). CONCLUSIONS: Muscle architectural properties are similar at rest in child athletes with different flexibility backgrounds. However, muscle fascicle elongation is greater in rhythmic gymnasts compared to volleyball athletes and this may contribute to the greater ankle ROM observed in rhythmic gymnasts.

scholarly journals Altered contractile properties of the gastrocnemius muscle poststroke

2008 ◽  
Vol 105 (6) ◽  
pp. 1802-1808 ◽  
Author(s):  
Fan Gao ◽  
Li-Qun Zhang
Keyword(s):  
Muscle Weakness ◽  
Gastrocnemius Muscle ◽  
Contractile Properties ◽  
Medial Gastrocnemius ◽  
Contractile Property ◽  
Stroke Survivors ◽  
Motor Impairments ◽  
Fascicle Length ◽  
Length Relationship ◽  
Muscle Fascicles

Spasticity, contracture and muscle weakness often occur together poststroke and cause considerable motor impairments to stroke survivors. The underlying changes in contractile properties of muscle fascicles are still not clear. The purpose of this study was to investigate the contractile property changes of the medial gastrocnemius muscle fascicles poststroke. Ten stroke survivors and ten healthy subjects participated in the study. The medial gastrocnemius fascicular length was measured at various combinations of ankle and knee positions using ultrasonography, with the muscle activated selectively using electrical stimulation. The stimulation intensity was kept constant across different ankle and knee positions to establish the active force-length relationship of the muscle fascicles. It was found that stroke survivors showed a shift of the force-length curve with a significantly shorter optimal fascicle length (33.2 ± 3.2 mm) compared with that of healthy controls (47.4 ± 2.7 mm) with P < 0.001. Furthermore, the width span of the fascicular force-length curve of stroke survivors was significantly narrower with steeper slopes than that of controls ( P ≤ 0.001), suggesting reduced number of sarcomeres along the fascicles and/or reduced sarcomere length poststroke. Regression analysis showed that the medial gastrocnemius fascicular length of stroke survivors varied significantly less with ankle and knee flexions ( P ≤ 0.001) than that of controls, suggesting shorter and stiffer muscle fascicles poststroke, which might be attributed to muscle architectural adaptation. This study showed that there are considerable changes in the contractile properties of muscle fascicles poststroke, which may contribute directly to the joint-level changes of decreased range of motion, increased stiffness, muscle weakness, and impaired motor functions in stroke survivors.

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