Stretching combined with repetitive small length changes of the plantar flexor muscles enhances their passive extensibility for longer duration than conventional static stretching, while not compromising strength

AbstractStatic stretching increases flexibility but can decrease muscle strength, and the method to avoid the latter has been longed for. In this study, a novel stretching modality was developed that provides repetitive small length changes to the plantar flexor muscles undergoing passive static stretching (“local vibration stretching,”). We investigated the effects of local vibration stretching on muscle strength, flexibility and its persistence. Plantar flexion strength and maximal ankle joint dorsiflexion angle (dorsiflexion range of motion) were measured for 10 healthy young males before (pre) and immediately after (post) three types of stretching: static stretching, local vibration stretching at 15 Hz, and no intervention (control). The dorsiflexion range of motion was measured also at 15, 30, and 60 min post-stretching. Elongation of the medial gastrocnemius and Achilles tendon was determined by ultrasonography. Plantar flexion strength significantly decreased by 4.3 ± 3.5 % in static stretching but not in local vibration stretching. The dorsiflexion range of motion significantly increased both in static stretching (7.2 ± 8.1 %) and local vibration stretching (11.2 ± 14.6 %) which was accompanied by a significantly larger muscle elongation but not tendon elongation. Elevated dorsiflexion range of motion was maintained until 30 min after the local vibration stretching while it returned to baseline level (pre-intervention) in 15 min after the static stretching. All variables remained unchanged in the control condition. In conclusion, local vibration stretching improves extensibility of the muscle belly without decreasing strength, and the increased flexibility is retained longer than static stretching.

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The single-leg heel raise does not predict maximal plantar flexion strength in healthy males and females

PLoS ONE ◽

10.1371/journal.pone.0253276 ◽

2021 ◽

Vol 16 (8) ◽

pp. e0253276

Author(s):

Lauren K. Sara ◽

Savannah B. Gutsch ◽

Sandra K. Hunter

Keyword(s):

Sex Differences ◽

Plantar Flexion ◽

Voluntary Activation ◽

Plantar Flexor ◽

Maximal Strength ◽

Flexor Muscles ◽

Males And Females ◽

Flexion Strength ◽

Plantar Flexor Muscles ◽

Flexor Strength

Introduction The single-leg heel raise test (SLHR) is commonly used in clinical settings to approximate plantar flexor strength, yet this is neither validated nor supported physiologically. The purposes of this study were to: determine (1) associations between SLHR repetitions, maximal plantar flexor strength, and reductions in strength; and (2) whether sex differences exist in performance of the SLHR. Methods Twenty-eight young, healthy participants (14 males,14 females, 19–30 years) performed repeated single-leg heel raises to task failure. Pre- and post-task measures included maximal voluntary isometric contractions (MVIC), and voluntary activation and contractile properties of the plantar flexor muscles, assessed using peripheral electrical stimulation of the tibial nerve. Surface electromyography was recorded for the medial and lateral gastrocnemius, soleus, and anterior tibialis muscles. Results The SLHR resulted in 20.5% reductions in MVIC torque (p<0.001). However, the number of SLHR repetitions was not correlated with either the baseline MVIC (maximal strength; p = 0.979) or the reduction in MVIC following the SLHR (p = 0.23). There were no sex differences in either the number of SLHR repetitions (p = 0.14), baseline MVIC torque (p = 0.198), or the reduction of MVIC (p = 0.14). MVIC decline was positively associated with the reduction in voluntary activation (r = 0.841, p<0.001), but was not associated with the change in twitch amplitude (p = 0.597). Conclusions The SLHR was similar in young males and females yet was a poor predictor of maximal plantar flexor strength but evaluates performance fatigability of the lower extremity specific to dynamic contractions. The reduction in maximal strength at task failure was explained by reduced neural drive to the plantar flexor muscles in both males and females. Impact statement SLHR performance is not a clinical assessment of plantar flexor strength but assesses dynamic lower extremity fatigability that is similar in males and females. Alternate clinical measures for maximal plantar flexion strength need to be developed.

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Immediate Effect of Kinesiotaping Applications on Ankle Range of Motion and Plantar Flexor Muscles Spasticity on Stroke Subjects

Proceedings of the International Meeting on Regenerative Medicine ◽

10.5220/0007321103300336 ◽

2017 ◽

Author(s):

Agustin Silfi Rahayu ◽

. Subagyo ◽

Patricia Maria K

Keyword(s):

Range Of Motion ◽

Plantar Flexor ◽

Flexor Muscles ◽

Plantar Flexor Muscles

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Acute effects of static stretching on muscle–tendon mechanics of quadriceps and plantar flexor muscles

European Journal of Applied Physiology ◽

10.1007/s00421-017-3618-9 ◽

2017 ◽

Vol 117 (7) ◽

pp. 1309-1315 ◽

Cited By ~ 7

Author(s):

Tom Bouvier ◽

Jules Opplert ◽

Carole Cometti ◽

Nicolas Babault

Keyword(s):

Plantar Flexor ◽

Static Stretching ◽

Acute Effects ◽

Tendon Mechanics ◽

Flexor Muscles ◽

Plantar Flexor Muscles

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Selected Measures of Ankle Dorsiflexion Range of Motion: Differences and Intercorrelations

Foot & Ankle ◽

10.1177/107110078901000209 ◽

1989 ◽

Vol 10 (2) ◽

pp. 99-103 ◽

Cited By ~ 27

Author(s):

Richard W. Bohannon ◽

David Tiberio ◽

Michael Zito

Keyword(s):

Range Of Motion ◽

Analysis Of Variance ◽

Ankle Dorsiflexion ◽

Plantar Flexor ◽

Plantar Surface ◽

Maximal Force ◽

Flexor Muscles ◽

Distal Surface ◽

The Subject ◽

Plantar Flexor Muscles

The purpose of this investigation was to describe and compare ankle dorsiflexion range of motion (ADROM) measurements obtained using the heel, fifth metatarsal, and plantar surface of foot as distal surface landmarks while the ankle was dorsiflexed under three conditions. The conditions were: 1) passive ankle dorsiflexion with force adequate to encounter notable tension in the plantar flexor muscles, 2) passive ankle dorsiflexion with a maximal force, and 3) as in number 2 but actively assisted by the subject. Thirty-six women had their ankles dorsiflexed three times under each of the three conditions. Slide photographs were taken of the procedure. The photographs were projected and ADROM measured using the three distal landmarks. Analysis of variance demonstrated that ADROM measurements were significantly different ( p < 0.001) under the three conditions of measurement and when the different landmarks were used. The majority (83.3%) of the ADROM measurements were correlated significantly ( P < .01) with one another regardless of the condition or landmark of measurement. Clinicians should be aware that measurements of ADROM will differ depending on the conditions of measurement and the landmarks used. Despite the differences, measurements obtained using various combinations of conditions and landmarks will provide an indication of ADROM.

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Robotic Shoe: An Ankle Assistive Device for Gait Plantar Flexion Assistance

2020 Design of Medical Devices Conference ◽

10.1115/dmd2020-9058 ◽

2020 ◽

Author(s):

Marcus Schaller ◽

Seyed Mostafa Rezayat Sorkhabadi ◽

Wenlong Zhang

Keyword(s):

Neurological Disorders ◽

Plantar Flexion ◽

Muscular Activity ◽

Assistive Device ◽

Walking Ability ◽

Constant Force ◽

Plantar Flexor ◽

Ankle Foot Orthoses ◽

Flexor Muscles ◽

Plantar Flexor Muscles

Abstract Gait disorders can be attributed to a variety of factors including aging, injury, and neurological disorders. A common disorder involves the ankle push-off phase of an individual’s gait, which is vital to their ability to walk and propel themselves forward. During the ankle push-off stage, plantar flexor muscles are required to provide a large amount of torque to propel the heel off the ground, thus a condition that compromises the strength of these muscles can greatly affect one’s walking ability. In order to rectify these issues, Ankle-Foot Orthoses (AFO) are used to provide support to a user’s ankle and assist with the force needed for heel off. This article introduces a robotic AFO which was developed with the intent of aiding during the heel-off stage. The proposed design utilizes the user’s body weight to extend constant force springs positioned parallel to the calf to replicate the muscular force generated in plantar flexion. The extended spring is held in place using a ratcheting mechanism which is released with a solenoid during heel up. Similar research has been conducted in which assistive AFO’s have been created, however little research has investigated the use of constant force springs in such devices. A healthy user tested the device on a treadmill and surface electromyography (sEMG) sensors were placed on the user’s plantar flexor muscles to monitor potential reductions in muscular activity resulting from the assistance provided by the AFO device. The data demonstrates the robotic shoe was able to assist during the heel-off stage and reduced activation in the plantar flexor muscles was evident from the EMG data collected.

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Effect of Superficial Heat, Deep Heat, and Active Exercise Warm-up on the Extensibility of the Plantar Flexors

Physical Therapy ◽

10.1093/ptj/81.6.1206 ◽

2001 ◽

Vol 81 (6) ◽

pp. 1206-1214 ◽

Cited By ~ 89

Author(s):

Claudia A Knight ◽

Carrie R Rutledge ◽

Michael E Cox ◽

Martha Acosta ◽

Susan J Hall

Keyword(s):

Plantar Flexor ◽

Static Stretching ◽

Warm Up ◽

Group 4 ◽

Flexor Muscles ◽

Group 3 ◽

Group 5 ◽

Group 2 ◽

Plantar Flexor Muscles ◽

Group 1

Abstract Background and Purpose. Warm-up prior to static stretching enhances muscle extensibility. The relative effectiveness of different modes of warm-up, however, is unknown. The purpose of this study was to evaluate the effectiveness of superficial heat, deep heat, and active exercise warm-up prior to stretching compared with stretching alone on the extensibility of the plantar-flexor muscles. Subjects. Ninety-seven subjects (59 women, 38 men) with limited dorsiflexion range of motion (ROM) were randomly assigned to 1 of 5 groups. Female subjects had a mean age of 27.6 years (SD=7.68, range=17–50), and male subjects had a mean age of 26.8 years (SD=6.87, range=18–48). Methods. The first group (group 1) was a control group and did not perform the stretching protocol. The 4 experimental groups (groups 2–5) performed a stretching protocol 3 days per week for 6 weeks. Group 2 performed the static stretching protocol only; group 3 performed active heel raises before stretching; group 4 received 15 minutes of superficial, moist heat to the plantar-flexor muscles before stretching; and group 5 received continuous ultrasound for 7 minutes before stretching. Dorsiflexion ROM measurements were taken initially and after 2, 4, and 6 weeks. Results. All experimental groups increased active and passive range of motion (AROM and PROM). The mean AROM/PROM differences at 6 weeks were 1.11/1.39 degrees for group 1, 4.10/6.11 degrees for group 2, 4.16/4.21 degrees for group 3, 4.38/4.90 degrees for group 4, and 6.20/7.35 degrees for group 5. The group receiving ultrasound before performing the stretching protocol (group 5) displayed the greatest increase in both AROM (6.20°) and PROM (7.35°). Discussion and Conclusion. Among the modalities tested, the use of ultrasound for 7 minutes prior to stretching may be the most effective for increasing ankle dorsiflexion ROM.

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Influence of Aerobic Exercise After Static Stretching on Flexibility and Strength in Plantar Flexor Muscles

Frontiers in Physiology ◽

10.3389/fphys.2020.612967 ◽

2020 ◽

Vol 11 ◽

Author(s):

Kosuke Takeuchi ◽

Masatoshi Nakamura

Keyword(s):

Aerobic Exercise ◽

Peak Torque ◽

Plantar Flexor ◽

Static Stretching ◽

Control Range ◽

Passive Torque ◽

Flexor Muscles ◽

Plantar Flexor Muscles ◽

Displacement Peak ◽

Healthy Males

Aerobic exercise could improve stretch-induced strength deficits. However, mechanisms of the improvement were unclear. The purpose of the study was to examine the effects of aerobic exercise after static stretching (SS) on flexibility and isometric strength in ankle plantar-flexor muscles. Fifteen healthy males received two interventions after SS of their ankle plantar-flexor muscles for 5 min. One was aerobic exercise for 10-min on a cycling ergometer, and the other was a 10-min rest as a control. Range of motion (ROM) of ankle dorsiflexion, passive torque at terminal ROM, muscle-tendon unit (MTU) stiffness, muscle tendon junction displacement, peak torque of ankle plantarflexion, and the amplitude of electromyography (EMG) were measured. Immediately after the SS, in both interventions, ROM, passive torque, and muscle tendon junction displacement increased significantly (p < 0.05), while MTU stiffness, peak torque, and the amplitude of EMG were significantly decreased (p < 0.05). After 10-min on a cycling ergometer, the decreased peak torque and amplitude of EMG indicated higher values than those before SS (p < 0.05), while MTU stiffness was no change. In conclusion, SS increased ROM because of the decreased MTU stiffness as well as increased tolerance for stretching. Aerobic exercise could increase the muscle strength and amplitude of EMG which decreased after static stretching.

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