scholarly journals Range of motion, neuromechanical, and architectural adaptations to plantar flexor stretch training in humans

2014 ◽  
Vol 117 (5) ◽  
pp. 452-462 ◽  
Author(s):  
A. J. Blazevich ◽  
D. Cannavan ◽  
C. M. Waugh ◽  
S. C. Miller ◽  
J. B. Thorlund ◽  
...  
Keyword(s):  
Range Of Motion ◽  
Muscle Activation ◽  
Joint Angle ◽  
Maximum Voluntary Contraction ◽  
Muscle Length ◽  
Joint Moment ◽  
Muscle Stiffness ◽  
Control Group ◽  
Plantar Flexor ◽  
Passive Joint

The neuromuscular adaptations in response to muscle stretch training have not been clearly described. In the present study, changes in muscle (at fascicular and whole muscle levels) and tendon mechanics, muscle activity, and spinal motoneuron excitability were examined during standardized plantar flexor stretches after 3 wk of twice daily stretch training (4 × 30 s). No changes were observed in a nonexercising control group ( n = 9), however stretch training elicited a 19.9% increase in dorsiflexion range of motion (ROM) and a 28% increase in passive joint moment at end ROM ( n = 12). Only a trend toward a decrease in passive plantar flexor moment during stretch (−9.9%; P = 0.15) was observed, and no changes in electromyographic amplitudes during ROM or at end ROM were detected. Decreases in Hmax:Mmax(tibial nerve stimulation) were observed at plantar flexed (gastrocnemius medialis and soleus) and neutral (soleus only) joint angles, but not with the ankle dorsiflexed. Muscle and fascicle strain increased (12 vs. 23%) along with a decrease in muscle stiffness (−18%) during stretch to a constant target joint angle. Muscle length at end ROM increased (13%) without a change in fascicle length, fascicle rotation, tendon elongation, or tendon stiffness following training. A lack of change in maximum voluntary contraction moment and rate of force development at any joint angle was taken to indicate a lack of change in series compliance of the muscle-tendon unit. Thus, increases in end ROM were underpinned by increases in maximum tolerable passive joint moment (stretch tolerance) and both muscle and fascicle elongation rather than changes in volitional muscle activation or motoneuron pool excitability.

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 Identification of Individual Muscle Length Parameters from Measurements of Passive Joint Moment Around the Ankle Joint

2012 ◽  
Vol 7 (2) ◽  
pp. 168-176 ◽  
Author(s):  
Hisashi NAITO ◽  
Yasushi AKAZAWA ◽  
Ayu MIURA ◽  
Takeshi MATSUMOTO ◽  
Masao TANAKA
Keyword(s):  
Ankle Joint ◽  
Muscle Length ◽  
Joint Moment ◽  
Passive Joint ◽  
Individual Muscle

Factors Affecting Force Loss With Prolonged Stretching

2001 ◽  
Vol 26 (3) ◽  
pp. 262-272 ◽  
Author(s):  
David G. Behm ◽  
Duane C. Button ◽  
Jeremy C. Butt
Keyword(s):  
Maximal Voluntary Contraction ◽  
Muscle Activation ◽  
Maximum Voluntary Contraction ◽  
Voluntary Contraction ◽  
Control Group ◽  
Tetanic Force ◽  
Factors Affecting ◽  
Passive Stretching ◽  
Interpolated Twitch Technique ◽  
Muscle Compliance

The purpose of this study was to investigate factors underlying the force loss occurring after prolonged, static, passive stretching. Subjects were tested before and 5-10 min following 20 min of static, passive stretching of the quadriceps (N = 12) or a similar period of no stretch (control, N = 6). Measurements included isometric maximal voluntary contraction (MVC) force, surface integrated electromyographic (iEMG) activity of the quadriceps and hamstrings, evoked contractile properties (twitch and tetanic force), and quadriceps inactivation as measured by the interpolated twitch technique (ITT). Following stretching, there was a significant 12% decrement in MVC with no significant changes in the control group. Muscle inactivation as measured by the ITT and iEMG increased by 2.8% and 20.2%, respectively. While twitch forces significantly decreased 11.7%, there was no change in tetanic force post-stretch. Although possible increases in muscle compliance affected twitch force, a lack of tetanic force change would suggest that post-stretch force decrements are more affected by muscle inactivation than changes in muscle elasticity. Key Words: antagonist, electromyography, maximum voluntary contraction, muscle activation, twitch, tetanus

Concentric muscle contractions before static stretching minimize, but do not remove, stretch-induced force deficits

2010 ◽  
Vol 108 (3) ◽  
pp. 637-645 ◽  
Author(s):  
Anthony D. Kay ◽  
Anthony J. Blazevich
Keyword(s):  
Achilles Tendon ◽  
Range Of Motion ◽  
Muscle Activity ◽  
Joint Moment ◽  
Triceps Surae ◽  
Medial Gastrocnemius ◽  
Plantar Flexor ◽  
Tendon Stiffness ◽  
Concentric Contractions ◽  
Time Motion

The effects of concentric contractions and passive stretching on musculotendinous stiffness and muscle activity were studied in 18 healthy human volunteers. Passive and concentric plantar flexor joint moment data were recorded on an isokinetic dynamometer with simultaneous electromyogram (EMG) monitoring of the triceps surae, real-time motion analysis of the lower leg, and ultrasound imaging of the Achilles-medial gastrocnemius muscle-tendon junction. The subjects then performed six 8-s ramped maximal voluntary concentric contractions before repeating both the passive and concentric trials. Concentric moment was significantly reduced (6.6%; P < 0.01), which was accompanied by, and correlated with ( r = 0.60–0.94; P < 0.05), significant reductions in peak triceps surae EMG amplitude (10.2%; P < 0.01). Achilles tendon stiffness was significantly reduced (11.7%; P < 0.01), but no change in gastrocnemius medialis muscle operating length was detected. The subjects then performed three 60-s static plantar flexor stretches before being retested 2 and 30 min poststretch. A further reduction in concentric joint moment (5.8%; P < 0.01) was detected poststretch at 90% of range of motion, with no decrease in muscle activity or Achilles tendon stiffness, but a significant increase in muscle operating length and decrease in tendon length was apparent at this range of motion ( P < 0.05). Thirty minutes after stretching, muscle activity significantly recovered to pre-maximal voluntary concentric contractions levels, whereas concentric moment and Achilles tendon stiffness remained depressed. These data show that the performance of maximal concentric contractions can substantially reduce neuromuscular activity and muscle force, but this does not prevent a further stretch-induced loss in active plantar flexor joint moment. Importantly, the different temporal changes in EMG and concentric joint moment indicate that a muscle-based mechanism was likely responsible for the force losses poststretch.

scholarly journals Short-Term Effects of Kinesio Taping Combined With Cervical Muscles Multi-angle Isometric Training in Patients With Cervical Spondylosis

2021 ◽  
Author(s):  
Jian Xiong ◽  
Zhe Zhang ◽  
Zhichao Zhang ◽  
Yan Ma ◽  
Zuhong Li ◽  
...  
Keyword(s):  
Resistance Training ◽  
Range Of Motion ◽  
Cervical Spondylosis ◽  
Clinical Symptoms ◽  
Muscle Stiffness ◽  
Control Group ◽  
Isometric Training ◽  
Cervical Range Of Motion ◽  
Kinesio Taping ◽  
Spine Function

Abstract Objective: The purpose of this study was to investigate the efficacy of Kinesio taping (KT) combined with multi-angle isometric resistance training for cervical spondylosis. Methods: Sixty-one patients were divided into two groups by random number table method. Both groups were given multi-angle isometric training, the patients in the observation group were supplemented with Kinesio taping. Before and after treatment, the symptoms of cervical spine function were evaluated in two groups by visual analogue scale (VAS), cervical dysfunction index (NDI), cervical range of motion and muscle stiffness.Results: After 3 weeks of treatment, VAS, NDI scores and the cervical range of motion were significantly better than before (P<0.05). The range of anterior flexion and extension was significantly larger than the control group (P<0.05), but the range of other motions were not certain. The muscle stiffness in KT group were significantly lower than the control group.Conclusion: KT combined with multi-angle isometric resistance training can further alleviate the clinical symptoms and correct the neck abnormal posture. But its effects on the range of cervical motion remain uncertain.

Neuromuscular factors influencing the maximum stretch limit of the human plantar flexors

2012 ◽  
Vol 113 (9) ◽  
pp. 1446-1455 ◽  
Author(s):  
A. J. Blazevich ◽  
D. Cannavan ◽  
C. M. Waugh ◽  
F. Fath ◽  
S. C. Miller ◽  
...  
Keyword(s):  
Range Of Motion ◽  
Injury Risk ◽  
Joint Moment ◽  
H Reflex ◽  
Plantar Flexors ◽  
Fascicle Length ◽  
Passive Joint ◽  
Factors Influencing ◽  
Tendon Lengthening ◽  
Maximum Range

Maximum joint range of motion is an important parameter influencing functional performance and musculoskeletal injury risk. Nonetheless, a complete description of the muscle architectural and tendon changes that occur during stretch and the factors influencing maximum range of motion is lacking. We measured muscle-tendon elongation and fascicle lengthening and rotation sonographically during maximal plantar flexor stretches in 21 healthy men. Electromyogram (EMG) recordings were obtained synchronously with ultrasound and joint moment data, and H-reflex measurements were made with the ankle at neutral (0°) and dorsiflexed (50% maximal passive joint moment) positions; the maximum H amplitude (normalized to maximum M-wave amplitude; Mmax) and H-amplitude elicited at a stimulation intensity that evoked 10% Mmaxwere obtained. Maximal stretch was accomplished through significant muscle (14.9%; 30 mm) and tendon lengthening (8.4%; 22 mm). There were similar relative changes in fascicle length and angle, but planimetric modeling indicated that the contribution of fascicle rotation to muscle lengthening was small (<4 mm). Subjects with a greater range of motion showed less resistance to stretch and a greater passive joint moment at stretch termination than less flexible subjects (i.e., greater stretch tolerance). Also, greater fascicle rotation accompanied muscle elongation (9.7 vs. 5.9%) and there was a greater tendon length at stretch termination in more flexible subjects. Finally, a moderate correlation between the angle of EMG onset and maximum range of motion was obtained ( r = 0.60, P < 0.05), despite there being no difference in H-reflex magnitudes between the groups. Thus clear differences in the neuromuscular responses to stretch were observed between “flexible” and “inflexible” subjects.

Isometric contractions reduce plantar flexor moment, Achilles tendon stiffness, and neuromuscular activity but remove the subsequent effects of stretch

2009 ◽  
Vol 107 (4) ◽  
pp. 1181-1189 ◽  
Author(s):  
Anthony D. Kay ◽  
Anthony J. Blazevich
Keyword(s):  
Achilles Tendon ◽  
Muscle Activity ◽  
Joint Moment ◽  
Triceps Surae ◽  
Medial Gastrocnemius ◽  
Isometric Contractions ◽  
Plantar Flexor ◽  
Tendon Stiffness ◽  
Neuromuscular Activity ◽  
Passive Joint

The effects of isometric contractions and passive stretching on muscle-tendon mechanics and muscle activity were studied in 16 healthy human volunteers. First, peak concentric and passive ankle joint moment data were recorded on an isokinetic dynamometer with electromyographic monitoring of the triceps surae; real-time motion analysis of the lower leg and ultrasound imaging of the Achilles-medial gastrocnemius muscle-tendon junction were simultaneously conducted. Second, the subjects performed six 8-s maximal voluntary isometric contractions (MVICs) before repeating the passive and active trials. Although there was no decrease in isometric joint moment after MVICs, peak concentric moment was significantly reduced (11.5%, P < 0.01). This was accompanied by, and correlated with ( r = 0.90, P < 0.01), significant reductions in peak triceps surae electromyographic amplitude (21.0%, P < 0.01). Achilles tendon stiffness (10.9%, P < 0.01) and passive joint moment (4.9%, P < 0.01) were also significantly reduced. Third, the subjects performed three 60-s static plantar flexor stretches before being retested 2 and 30 min after stretch. The stretch protocol caused no significant change in any measure. At 30 min after stretching, significant recovery in concentric moment and muscle activity was detected at dorsiflexed joint angles, while Achilles tendon stiffness and passive joint moment remained significantly reduced. These data show that the performance of MVICs interrupts the normal stretch-induced losses in active and passive plantar flexor joint moment and neuromuscular activity, largely because concentric strength and tendon properties were already affected. Importantly, the decrease in Achilles tendon stiffness remained 30 min later, which may be an important etiological factor for muscle-tendon strain injury risk.

scholarly journals Plantar-flexor static stretch training effect on eccentric and concentric peak torque – a comparative study of trained versus untrained subjects

2012 ◽  
Vol 34 (1) ◽  
pp. 49-58 ◽  
Author(s):  
Amr Almaz Abdel-aziem ◽  
Walaa Sayed Mohammad
Keyword(s):  
Range Of Motion ◽  
Systemic Disease ◽  
Previous History ◽  
Control Group ◽  
Plantar Flexor ◽  
Static Stretching ◽  
Long Term Effects ◽  
Plantar Flexors ◽  
Angular Velocities ◽  
History Of

AbstractThe aim of this study was to examine the long-term effects of static stretching of the plantar-flexor muscles oneccentric and concentric torque and ankle dorsiflexion range of motion in healthy subjects. Seventy five healthy malevolunteers, with no previous history of trauma to the calf that required surgery, absence of knee flexion contracture andno history of neurologic dysfunction or disease, systemic disease affecting the lower extremities were selected for thisstudy. The participants were divided into three equal groups. The control group did not stretch the plantar-flexormuscles. Two Experimental groups (trained and untrained) were instructed to perform static stretching exercise of 30second duration and 5 repetitions twice daily. The stretching sessions were carried out 5 days a week for 6 weeks. Thedorsiflexion range of motion was measured in all subjects. Also measured was the eccentric and concentric torque ofplantar-flexors at angular velocities of 30 and 120o/s pre and post stretching. Analysis of variance showed a significantincrease in plantar-flexor eccentric and concentric torque (p < 0.05) of trained and untrained groups, and an increase indorsiflexion range of motion (p < 0.05) at both angular velocities for the untrained group only. The static stretchingprogram of plantar-flexors was effective in increasing the concentric and eccentric plantarflexion torque at angularvelocities of 30 and 120o/s. Increases in plantar-flexors flexibility were observed in untrained subjects.

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