The relationship between passive ankle plantar flexion joint torque and gastrocnemius muscle and achilles tendon stiffness

Implications for flexibility

Yasuo Kawakami, Hiroaki Kanehisa, Tetsuo Fukunaga

Research output: Contribution to journalArticle

38 Citations (Scopus)

Abstract

Fish eye STUDY DESIGN: Experimental laboratory study. Fish eye OBJECTIVES: We tested the hypothesis that the muscle fibers and the connective tendinous structures, combined in series, provide the resistance to passive joint movement at the ankle. We also determined the relative association between passive joint torque and each of these 2 elements. Fish eye BACKGROUND: The reason for individual variation in joint flexibility or tightness is not clearly understood, but the influence of musculotendinous stiffness has been inferred. Fish eye METHODS AND MEASURES: Each of the subjects (6 women and 6 men) was seated with the right knee extended and right ankle positioned at a 30°, 20°, 10°, 0°, -10°, -20°, and -30° (0, neutral position, positive values reflecting plantar flexion) angle while passive plantar flexion torque was measured. The distal muscle-tendon junction of the medial gastrocnemius was visualized by ultrasonography, and its positional change was defined as muscle belly length change. The whole muscle-tendon unit length change was estimated from joint angle changes, from which Achilles tendon length change was estimated. Fish eye RESULTS: Both the muscle belly and tendon were significantly elongated as the ankle was dorsiflexed (at 0° the mean ±SD muscle belly elongation was 10.3% ±1.8%, and the tendon elongation was 2.8% ±1.2%, of the initial length of their respective structures measured at 30° of ankle plantar flexion), from which stiffness indices were determined both for muscle belly and tendon. The passive torque at 0°, -10°, -20°, and -30° was significantly correlated with the stiffness indices of the Achilles tendon (at 0°, r2 = 0.70 and 0.62 for overall and specific stiffness, respectively; P<.05). A tendon stiffness index, separately obtained from tendon lengthening during maximal isometric contraction, was also correlated with passive ankle plantar flexion torque at 0°, -10°, -20°, and -30° (at 0°, r2 = 0.76, P<.05). The specific stiffness index of the muscle belly was correlated (r2 = 0.47, P<.05) with the passive ankle plantar flexion torque at 0°, but its overall stiffness index was not (r2 = 0.32,P>.05). Fish eye CONCLUSION: Results suggest that extensibility of the muscle-tendon unit of the Achilles tendon for the most part is related to passive ankle plantar flexion joint torque.

Original languageEnglish
Pages (from-to)269-276
Number of pages8
JournalJournal of Orthopaedic and Sports Physical Therapy
Volume38
Issue number5
DOIs
Publication statusPublished - 2008 May

Fingerprint

Achilles Tendon
Torque
Ankle
Skeletal Muscle
Joints
Tendons
Muscles
Fishes
Articular Range of Motion
Ultrasonography
Knee

Keywords

  • Dorsiflexion
  • Flexibility
  • Plantar flexors
  • Stretching

ASJC Scopus subject areas

  • Physical Therapy, Sports Therapy and Rehabilitation
  • Health Professions(all)

Cite this

@article{7430798c317d4f009168bfa4e3dc5aa1,
title = "The relationship between passive ankle plantar flexion joint torque and gastrocnemius muscle and achilles tendon stiffness: Implications for flexibility",
abstract = "Fish eye STUDY DESIGN: Experimental laboratory study. Fish eye OBJECTIVES: We tested the hypothesis that the muscle fibers and the connective tendinous structures, combined in series, provide the resistance to passive joint movement at the ankle. We also determined the relative association between passive joint torque and each of these 2 elements. Fish eye BACKGROUND: The reason for individual variation in joint flexibility or tightness is not clearly understood, but the influence of musculotendinous stiffness has been inferred. Fish eye METHODS AND MEASURES: Each of the subjects (6 women and 6 men) was seated with the right knee extended and right ankle positioned at a 30°, 20°, 10°, 0°, -10°, -20°, and -30° (0, neutral position, positive values reflecting plantar flexion) angle while passive plantar flexion torque was measured. The distal muscle-tendon junction of the medial gastrocnemius was visualized by ultrasonography, and its positional change was defined as muscle belly length change. The whole muscle-tendon unit length change was estimated from joint angle changes, from which Achilles tendon length change was estimated. Fish eye RESULTS: Both the muscle belly and tendon were significantly elongated as the ankle was dorsiflexed (at 0° the mean ±SD muscle belly elongation was 10.3{\%} ±1.8{\%}, and the tendon elongation was 2.8{\%} ±1.2{\%}, of the initial length of their respective structures measured at 30° of ankle plantar flexion), from which stiffness indices were determined both for muscle belly and tendon. The passive torque at 0°, -10°, -20°, and -30° was significantly correlated with the stiffness indices of the Achilles tendon (at 0°, r2 = 0.70 and 0.62 for overall and specific stiffness, respectively; P<.05). A tendon stiffness index, separately obtained from tendon lengthening during maximal isometric contraction, was also correlated with passive ankle plantar flexion torque at 0°, -10°, -20°, and -30° (at 0°, r2 = 0.76, P<.05). The specific stiffness index of the muscle belly was correlated (r2 = 0.47, P<.05) with the passive ankle plantar flexion torque at 0°, but its overall stiffness index was not (r2 = 0.32,P>.05). Fish eye CONCLUSION: Results suggest that extensibility of the muscle-tendon unit of the Achilles tendon for the most part is related to passive ankle plantar flexion joint torque.",
keywords = "Dorsiflexion, Flexibility, Plantar flexors, Stretching",
author = "Yasuo Kawakami and Hiroaki Kanehisa and Tetsuo Fukunaga",
year = "2008",
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language = "English",
volume = "38",
pages = "269--276",
journal = "Journal of Orthopaedic and Sports Physical Therapy",
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TY - JOUR

T1 - The relationship between passive ankle plantar flexion joint torque and gastrocnemius muscle and achilles tendon stiffness

T2 - Implications for flexibility

AU - Kawakami, Yasuo

AU - Kanehisa, Hiroaki

AU - Fukunaga, Tetsuo

PY - 2008/5

Y1 - 2008/5

N2 - Fish eye STUDY DESIGN: Experimental laboratory study. Fish eye OBJECTIVES: We tested the hypothesis that the muscle fibers and the connective tendinous structures, combined in series, provide the resistance to passive joint movement at the ankle. We also determined the relative association between passive joint torque and each of these 2 elements. Fish eye BACKGROUND: The reason for individual variation in joint flexibility or tightness is not clearly understood, but the influence of musculotendinous stiffness has been inferred. Fish eye METHODS AND MEASURES: Each of the subjects (6 women and 6 men) was seated with the right knee extended and right ankle positioned at a 30°, 20°, 10°, 0°, -10°, -20°, and -30° (0, neutral position, positive values reflecting plantar flexion) angle while passive plantar flexion torque was measured. The distal muscle-tendon junction of the medial gastrocnemius was visualized by ultrasonography, and its positional change was defined as muscle belly length change. The whole muscle-tendon unit length change was estimated from joint angle changes, from which Achilles tendon length change was estimated. Fish eye RESULTS: Both the muscle belly and tendon were significantly elongated as the ankle was dorsiflexed (at 0° the mean ±SD muscle belly elongation was 10.3% ±1.8%, and the tendon elongation was 2.8% ±1.2%, of the initial length of their respective structures measured at 30° of ankle plantar flexion), from which stiffness indices were determined both for muscle belly and tendon. The passive torque at 0°, -10°, -20°, and -30° was significantly correlated with the stiffness indices of the Achilles tendon (at 0°, r2 = 0.70 and 0.62 for overall and specific stiffness, respectively; P<.05). A tendon stiffness index, separately obtained from tendon lengthening during maximal isometric contraction, was also correlated with passive ankle plantar flexion torque at 0°, -10°, -20°, and -30° (at 0°, r2 = 0.76, P<.05). The specific stiffness index of the muscle belly was correlated (r2 = 0.47, P<.05) with the passive ankle plantar flexion torque at 0°, but its overall stiffness index was not (r2 = 0.32,P>.05). Fish eye CONCLUSION: Results suggest that extensibility of the muscle-tendon unit of the Achilles tendon for the most part is related to passive ankle plantar flexion joint torque.

AB - Fish eye STUDY DESIGN: Experimental laboratory study. Fish eye OBJECTIVES: We tested the hypothesis that the muscle fibers and the connective tendinous structures, combined in series, provide the resistance to passive joint movement at the ankle. We also determined the relative association between passive joint torque and each of these 2 elements. Fish eye BACKGROUND: The reason for individual variation in joint flexibility or tightness is not clearly understood, but the influence of musculotendinous stiffness has been inferred. Fish eye METHODS AND MEASURES: Each of the subjects (6 women and 6 men) was seated with the right knee extended and right ankle positioned at a 30°, 20°, 10°, 0°, -10°, -20°, and -30° (0, neutral position, positive values reflecting plantar flexion) angle while passive plantar flexion torque was measured. The distal muscle-tendon junction of the medial gastrocnemius was visualized by ultrasonography, and its positional change was defined as muscle belly length change. The whole muscle-tendon unit length change was estimated from joint angle changes, from which Achilles tendon length change was estimated. Fish eye RESULTS: Both the muscle belly and tendon were significantly elongated as the ankle was dorsiflexed (at 0° the mean ±SD muscle belly elongation was 10.3% ±1.8%, and the tendon elongation was 2.8% ±1.2%, of the initial length of their respective structures measured at 30° of ankle plantar flexion), from which stiffness indices were determined both for muscle belly and tendon. The passive torque at 0°, -10°, -20°, and -30° was significantly correlated with the stiffness indices of the Achilles tendon (at 0°, r2 = 0.70 and 0.62 for overall and specific stiffness, respectively; P<.05). A tendon stiffness index, separately obtained from tendon lengthening during maximal isometric contraction, was also correlated with passive ankle plantar flexion torque at 0°, -10°, -20°, and -30° (at 0°, r2 = 0.76, P<.05). The specific stiffness index of the muscle belly was correlated (r2 = 0.47, P<.05) with the passive ankle plantar flexion torque at 0°, but its overall stiffness index was not (r2 = 0.32,P>.05). Fish eye CONCLUSION: Results suggest that extensibility of the muscle-tendon unit of the Achilles tendon for the most part is related to passive ankle plantar flexion joint torque.

KW - Dorsiflexion

KW - Flexibility

KW - Plantar flexors

KW - Stretching

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JO - Journal of Orthopaedic and Sports Physical Therapy

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