Heterogeneity of muscle activation in relation to force direction: A multi-channel surface electromyography study on the triceps surae muscle

2009 ◽  
Vol 19 (5) ◽  
pp. 882-895 ◽  
Author(s):  
D. Staudenmann ◽  
I. Kingma ◽  
A. Daffertshofer ◽  
D.F. Stegeman ◽  
J.H. van Dieën
Keyword(s):  
Surface Electromyography ◽  
Muscle Activation ◽  
Triceps Surae ◽  
Triceps Surae Muscle ◽  
Channel Surface ◽  
Force Direction

scholarly journals Older Adults Overcome Reduced Triceps Surae Structural Stiffness to Preserve Ankle Joint Quasi-Stiffness During Walking

2020 ◽  
Vol 36 (4) ◽  
pp. 209-216
Author(s):  
Rebecca L. Krupenevich ◽  
William H. Clark ◽  
Gregory S. Sawicki ◽  
Jason R. Franz
Keyword(s):  
Older Adults ◽  
Young Adults ◽  
Achilles Tendon ◽  
Ankle Joint ◽  
Muscle Activation ◽  
Muscle Stiffness ◽  
Triceps Surae ◽  
Triceps Surae Muscle ◽  
Age Related ◽  
Lower Ankle Joint

Ankle joint quasi-stiffness is an aggregate measure of the interaction between triceps surae muscle stiffness and Achilles tendon stiffness. This interaction may be altered due to age-related changes in the structural properties and functional behavior of the Achilles tendon and triceps surae muscles. The authors hypothesized that, due to a more compliant of Achilles’ tendon, older adults would exhibit lower ankle joint quasi-stiffness than young adults during walking and during isolated contractions at matched triceps surae muscle activations. The authors also hypothesized that, independent of age, triceps surae muscle stiffness and ankle joint quasi-stiffness would increase with triceps surae muscle activation. The authors used conventional gait analysis in one experiment and, in another, electromyographic biofeedback and in vivo ultrasound imaging applied during isolated contractions. The authors found no difference in ankle joint quasi-stiffness between young and older adults during walking. Conversely, this study found that (1) young and older adults modulated ankle joint quasi-stiffness via activation-dependent changes in triceps surae muscle length–tension behavior and (2) at matched activation, older adults exhibited lower ankle joint quasi-stiffness than young adults. Despite age-related reductions during isolated contractions, ankle joint quasi-stiffness was maintained in older adults during walking, which may be governed via activation-mediated increases in muscle stiffness.

scholarly journals Applying Stretch to Evoke Hyperreflexia in Spasticity Testing: Velocity vs. Acceleration

2021 ◽  
Vol 8 ◽  
Author(s):  
Lizeth H. Sloot ◽  
Guido Weide ◽  
Marjolein M. van der Krogt ◽  
Kaat Desloovere ◽  
Jaap Harlaar ◽  
...  
Keyword(s):  
Muscle Activation ◽  
Peak Velocity ◽  
Neurological Diseases ◽  
Maximum Velocity ◽  
Triceps Surae ◽  
Medial Gastrocnemius ◽  
Reflex Response ◽  
Movement Initiation ◽  
Maximum Acceleration ◽  
Triceps Surae Muscle

In neurological diseases, muscles often become hyper-resistant to stretch due to hyperreflexia, an exaggerated stretch reflex response that is considered to primarily depend on the muscle's stretch velocity. However, there is still limited understanding of how different biomechanical triggers applied during clinical tests evoke these reflex responses. We examined the effect of imposing a rotation with increasing velocity vs. increasing acceleration on triceps surae muscle repsonse in children with spastic paresis (SP) and compared the responses to those measured in typically developing (TD) children. A motor-operated ankle manipulator was used to apply different bell-shaped movement profiles, with three levels of maximum velocity (70, 110, and 150°/s) and three levels of maximum acceleration (500, 750, and 1,000°/s2). For each profile and both groups, we evaluated the amount of evoked triceps surae muscle activation. In SP, we evaluated two additional characteristics: the intensity of the response (peak EMG burst) and the time from movement initiation to onset of the EMG burst. As expected, the amount of evoked muscle activation was larger in SP compared to TD (all muscles: p < 0.001) and only sensitive to biomechanical triggers in SP. Further investigation of the responses in SP showed that peak EMG bursts increased in profiles with higher peak velocity (lateral gastrocnemius: p = 0.04), which was emphasized by fair correlations with increased velocity at EMG burst onset (all muscles: r > 0.33–0.36, p ≤ 0.008), but showed no significant effect for acceleration. However, the EMG burst was evoked faster with higher peak acceleration (all muscles p < 0.001) whereas it was delayed in profiles with higher peak velocity (medial gastrocnemius and soleus: p < 0.006). We conclude that while exaggerated response intensity (peak EMG burst) seems linked to stretch velocity, higher accelerations seem to evoke faster responses (time to EMG burst onset) in triceps surae muscles in SP. Understanding and controlling for the distinct effects of different biological triggers, including velocity, acceleration but also length and force of the applied movement, will contribute to the development of more precise clinical measurement tools. This is especially important when aiming to understand the role of hyperreflexia during functional movements where the biomechanical inputs are multiple and changing.

scholarly journals The effects of triceps surae muscle stimulation on localized achilles subtendon tissue displacements

2021 ◽  
Author(s):  
Nathan L. Lehr ◽  
William H. Clark ◽  
Michael D. Lewek ◽  
Jason R. Franz
Keyword(s):  
Achilles Tendon ◽  
Muscle Activation ◽  
Triceps Surae ◽  
Medial Gastrocnemius ◽  
Muscle Stimulation ◽  
Triceps Surae Muscle ◽  
Ankle Angle ◽  
In Series ◽  
Fixed End

The triceps surae muscle tendon unit is comprised of the lateral and medial gastrocnemius (MG) and soleus (SOL) muscles and three in series elastic “subtendons” that form the Achilles tendon. Comparative literature and our own in vivo evidence suggests that sliding between adjacent subtendons may facilitate independent muscle actuation. We aim to more clearly define the relation between individual muscle activation and subtendon tissue displacements. Here, during fixed-end contractions, electrical muscle stimulation controlled the magnitude of force transmitted via individual triceps surae muscles while ultrasound imaging recorded resultant subtendon tissue displacements. We hypothesized that MG and SOL stimulation would elicit larger displacements in their associated subtendon. 10 young adults completed 4 experimental activations at 3 ankle angles (-20°, 0°, 20°) with knee flexed to approximately 20°: MG stimulation (STIMMG), SOL stimulation (STIMSOL), combined stimulation, and volitional contraction. At 20° plantarflexion, STIMSOL elicited 49% larger tendon non-uniformity (SOL – MG subtendon tissue displacement) than that of STIMMG (p=0.004). For STIMSOL, a one-way post-hoc ANOVA revealed a significant main effect of ankle angle (p=0.009) on Achilles tendon non-uniformity. However, peak tendon non-uniformity decreased by an average of 61% from plantarflexion to dorsiflexion, likely due to an increase in passive tension. Our results suggest that localized tissue displacements within the Achilles tendon respond in anatomically consistent ways to differential patterns of triceps surae muscle activation, but these relations are highly susceptible to ankle angle. This in vivo evidence points to at least some mechanical independence in actuation between the human triceps surae muscle-subtendon units.

scholarly journals Bilateral triceps surae muscle focal myositis after a cauda equina syndrome

2021 ◽  
Author(s):  
G.R. González Toledo ◽  
H. Pérez Pérez ◽  
L. Brage Martín ◽  
V. Castro López-Tarruella
Keyword(s):  
Cauda Equina Syndrome ◽  
Cauda Equina ◽  
Triceps Surae ◽  
Triceps Surae Muscle

scholarly journals The effects of 12 weeks of static stretch training on the functional, mechanical, and architectural characteristics of the triceps surae muscle–tendon complex

2021 ◽  
Author(s):  
Stefano Longo ◽  
Emiliano Cè ◽  
Angela Valentina Bisconti ◽  
Susanna Rampichini ◽  
Christian Doria ◽  
...  
Keyword(s):  
Muscle Activation ◽  
Maximum Voluntary Contraction ◽  
Muscle Stiffness ◽  
Triceps Surae ◽  
Maximum Force ◽  
Passive Stiffness ◽  
Electromechanical Delay ◽  
Fascicle Length ◽  
Generating Capacity ◽  
Plantarflexor Muscles

Abstract Purpose We investigated the effects of 12 weeks of passive static stretching training (PST) on force-generating capacity, passive stiffness, muscle architecture of plantarflexor muscles. Methods Thirty healthy adults participated in the study. Fifteen participants (STR, 6 women, 9 men) underwent 12-week plantarflexor muscles PST [(5 × 45 s-on/15 s-off) × 2exercises] × 5times/week (duration: 2250 s/week), while 15 participants (CTRL, 6 women, 9 men) served as control (no PST). Range of motion (ROM), maximum passive resistive torque (PRTmax), triceps surae architecture [fascicle length, fascicle angle, and thickness], passive stiffness [muscle–tendon complex (MTC) and muscle stiffness], and plantarflexors maximun force-generating capacity variables (maximum voluntary contraction, maximum muscle activation, rate of torque development, electromechanical delay) were calculated Pre, at the 6th (Wk6), and the 12th week (Wk12) of the protocol in both groups. Results Compared to Pre, STR ROM increased (P < 0.05) at Wk6 (8%) and Wk12 (23%). PRTmax increased at Wk12 (30%, P < 0.05), while MTC stiffness decreased (16%, P < 0.05). Muscle stiffness decreased (P < 0.05) at Wk6 (11%) and Wk12 (16%). No changes in triceps surae architecture and plantarflexors maximum force-generating capacity variables were found in STR (P > 0.05). Percentage changes in ROM correlated with percentage changes in PRTmax (ρ = 0.62, P = 0.01) and MTC stiffness (ρ = − 0.78, P = 0.001). In CTRL, no changes (P > 0.05) occurred in any variables at any time point. Conclusion The expected long-term PST-induced changes in ROM were associated with modifications in the whole passive mechanical properties of the ankle joint, while maximum force-generating capacity characteristics were preserved. 12 weeks of PST do not seem a sufficient stimulus to induce triceps surae architectural changes.

scholarly journals Muscle Heating With Megapulse II Shortwave Diathermy and ReBound Diathermy

2013 ◽  
Vol 48 (4) ◽  
pp. 477-482 ◽  
Author(s):  
David O. Draper ◽  
Amanda R. Hawkes ◽  
A. Wayne Johnson ◽  
Mike T. Diede ◽  
Justin H. Rigby
Keyword(s):  
Heat Dissipation ◽  
Subcutaneous Fat ◽  
Muscle Group ◽  
Triceps Surae ◽  
Tissue Temperature ◽  
Measured Temperature ◽  
Temperature Decay ◽  
Triceps Surae Muscle ◽  
Subcutaneous Fat Thickness ◽  
Shortwave Diathermy

Context: A new continuous diathermy called ReBound recently has been introduced. Its effectiveness as a heating modality is unknown. Objective: To compare the effects of the ReBound diathermy with an established deep-heating diathermy, the Megapulse II pulsed shortwave diathermy, on tissue temperature in the human triceps surae muscle. Design:  Crossover study. Setting: University research laboratory. Patients or Other Participants: Participants included 12 healthy, college-aged volunteers (4 men, 8 women; age = 22.2 ± 2.25 years, calf subcutaneous fat thickness = 7.2 ± 1.9 mm). Intervention(s):  Each modality treatment was applied to the triceps surae muscle group of each participant for 30 minutes. After 30 minutes, we removed the modality and recorded temperature decay for 20 minutes. Main Outcome Measure(s): We horizontally inserted an implantable thermocouple into the medial triceps surae muscle to measure intramuscular tissue temperature at 3 cm deep. We measured temperature every 5 minutes during the 30-minute treatment and each minute during the 20-minute temperature decay. Results: Tissue temperature at a depth of 3 cm increased more with Megapulse II than with ReBound diathermy over the course of the treatment (F6,66 = 10.78, P &lt; .001). ReBound diathermy did not produce as much intramuscular heating, leading to a slower heat dissipation rate than the Megapulse II (F20,220 = 28.84, P &lt; .001). Conclusions:  During a 30-minute treatment, the Megapulse II was more effective than ReBound diathermy at increasing deep, intramuscular tissue temperature of the triceps surae muscle group.

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