Acute effects of contract-relax (CR) stretch versus a modified CR technique

Anthony D Kay, Steven Dods, Anthony J Blazevich

Research output: Contribution to journalArticle

Abstract

Purpose Contract–relax (CR) stretching increases range of motion (ROM) substantively, however its use in athletic environments is limited as the contractions performed in a highly stretched position require partner assistance, are often painful, and may induce muscle damage. Therefore, the acute effects of performing the contractions ‘off stretch’ in the anatomical position [stretch–return–contract (SRC)] were compared with traditional CR stretching in 14 healthy human volunteers. Methods Passive ankle joint moment and dorsiflexion ROM were recorded on an isokinetic dynamometer with electromyographic monitoring of the triceps surae, whilst simultaneous real-time motion analysis and ultrasound imaging recorded gastrocnemius medialis muscle and Achilles tendon elongation. The subjects then performed CR or SRC stretches (4 × 10-s stretches and 5-s contractions) randomly on separate days before reassessment. Results Significant increases in dorsiflexion ROM (4.1°– 4.0°; P < 0.01) and peak passive moment (10.9– 15.1 %; P < 0.05) and decreases in the slope of the passive moment curve (19.1–13.3 %; P < 0.05), muscle stiffness (21.7– 21.3 %; P < 0.01) and tendon stiffness (20.4–15.7 %; P < 0.01) were observed in CR and SRC, respectively. No between-condition differences were found in any measure (P > 0.05). Conclusions Similar mechanical and neurological changes were observed between conditions, indicating that identical mechanisms underpin the ROM improvements. These data have important practical implications for the use of this stretching mode in athletic environments as performing the contractions ‘off stretch’ eliminates the pain response, reduces the risk of inducing muscle damage, and removes the need for partner assistance. Thus, it represents an equally effective, simpler, and yet potentially safer, stretching paradigm.
Original languageEnglish
Pages (from-to)611-621
Number of pages11
JournalEuropean Journal of Applied Physiology
Volume116
Issue number3
Early online date4 Jan 2016
DOIs
Publication statusPublished - 1 Mar 2016

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Contracts
Articular Range of Motion
Sports
Muscles
Achilles Tendon
Ankle Joint
Ultrasonography
Healthy Volunteers
Skeletal Muscle
Pain

Keywords

  • Proprioceptive neuromuscular facilitation
  • range of motion
  • tendon stiffness
  • ultrasound

Cite this

Kay, Anthony D ; Dods, Steven ; Blazevich, Anthony J. / Acute effects of contract-relax (CR) stretch versus a modified CR technique. In: European Journal of Applied Physiology. 2016 ; Vol. 116, No. 3. pp. 611-621.
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abstract = "Purpose Contract–relax (CR) stretching increases range of motion (ROM) substantively, however its use in athletic environments is limited as the contractions performed in a highly stretched position require partner assistance, are often painful, and may induce muscle damage. Therefore, the acute effects of performing the contractions ‘off stretch’ in the anatomical position [stretch–return–contract (SRC)] were compared with traditional CR stretching in 14 healthy human volunteers. Methods Passive ankle joint moment and dorsiflexion ROM were recorded on an isokinetic dynamometer with electromyographic monitoring of the triceps surae, whilst simultaneous real-time motion analysis and ultrasound imaging recorded gastrocnemius medialis muscle and Achilles tendon elongation. The subjects then performed CR or SRC stretches (4 × 10-s stretches and 5-s contractions) randomly on separate days before reassessment. Results Significant increases in dorsiflexion ROM (4.1°– 4.0°; P < 0.01) and peak passive moment (10.9– 15.1 {\%}; P < 0.05) and decreases in the slope of the passive moment curve (19.1–13.3 {\%}; P < 0.05), muscle stiffness (21.7– 21.3 {\%}; P < 0.01) and tendon stiffness (20.4–15.7 {\%}; P < 0.01) were observed in CR and SRC, respectively. No between-condition differences were found in any measure (P > 0.05). Conclusions Similar mechanical and neurological changes were observed between conditions, indicating that identical mechanisms underpin the ROM improvements. These data have important practical implications for the use of this stretching mode in athletic environments as performing the contractions ‘off stretch’ eliminates the pain response, reduces the risk of inducing muscle damage, and removes the need for partner assistance. Thus, it represents an equally effective, simpler, and yet potentially safer, stretching paradigm.",
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Acute effects of contract-relax (CR) stretch versus a modified CR technique. / Kay, Anthony D; Dods, Steven; Blazevich, Anthony J.

In: European Journal of Applied Physiology, Vol. 116, No. 3, 01.03.2016, p. 611-621.

Research output: Contribution to journalArticle

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T1 - Acute effects of contract-relax (CR) stretch versus a modified CR technique

AU - Kay, Anthony D

AU - Dods, Steven

AU - Blazevich, Anthony J

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N2 - Purpose Contract–relax (CR) stretching increases range of motion (ROM) substantively, however its use in athletic environments is limited as the contractions performed in a highly stretched position require partner assistance, are often painful, and may induce muscle damage. Therefore, the acute effects of performing the contractions ‘off stretch’ in the anatomical position [stretch–return–contract (SRC)] were compared with traditional CR stretching in 14 healthy human volunteers. Methods Passive ankle joint moment and dorsiflexion ROM were recorded on an isokinetic dynamometer with electromyographic monitoring of the triceps surae, whilst simultaneous real-time motion analysis and ultrasound imaging recorded gastrocnemius medialis muscle and Achilles tendon elongation. The subjects then performed CR or SRC stretches (4 × 10-s stretches and 5-s contractions) randomly on separate days before reassessment. Results Significant increases in dorsiflexion ROM (4.1°– 4.0°; P < 0.01) and peak passive moment (10.9– 15.1 %; P < 0.05) and decreases in the slope of the passive moment curve (19.1–13.3 %; P < 0.05), muscle stiffness (21.7– 21.3 %; P < 0.01) and tendon stiffness (20.4–15.7 %; P < 0.01) were observed in CR and SRC, respectively. No between-condition differences were found in any measure (P > 0.05). Conclusions Similar mechanical and neurological changes were observed between conditions, indicating that identical mechanisms underpin the ROM improvements. These data have important practical implications for the use of this stretching mode in athletic environments as performing the contractions ‘off stretch’ eliminates the pain response, reduces the risk of inducing muscle damage, and removes the need for partner assistance. Thus, it represents an equally effective, simpler, and yet potentially safer, stretching paradigm.

AB - Purpose Contract–relax (CR) stretching increases range of motion (ROM) substantively, however its use in athletic environments is limited as the contractions performed in a highly stretched position require partner assistance, are often painful, and may induce muscle damage. Therefore, the acute effects of performing the contractions ‘off stretch’ in the anatomical position [stretch–return–contract (SRC)] were compared with traditional CR stretching in 14 healthy human volunteers. Methods Passive ankle joint moment and dorsiflexion ROM were recorded on an isokinetic dynamometer with electromyographic monitoring of the triceps surae, whilst simultaneous real-time motion analysis and ultrasound imaging recorded gastrocnemius medialis muscle and Achilles tendon elongation. The subjects then performed CR or SRC stretches (4 × 10-s stretches and 5-s contractions) randomly on separate days before reassessment. Results Significant increases in dorsiflexion ROM (4.1°– 4.0°; P < 0.01) and peak passive moment (10.9– 15.1 %; P < 0.05) and decreases in the slope of the passive moment curve (19.1–13.3 %; P < 0.05), muscle stiffness (21.7– 21.3 %; P < 0.01) and tendon stiffness (20.4–15.7 %; P < 0.01) were observed in CR and SRC, respectively. No between-condition differences were found in any measure (P > 0.05). Conclusions Similar mechanical and neurological changes were observed between conditions, indicating that identical mechanisms underpin the ROM improvements. These data have important practical implications for the use of this stretching mode in athletic environments as performing the contractions ‘off stretch’ eliminates the pain response, reduces the risk of inducing muscle damage, and removes the need for partner assistance. Thus, it represents an equally effective, simpler, and yet potentially safer, stretching paradigm.

KW - Proprioceptive neuromuscular facilitation

KW - range of motion

KW - tendon stiffness

KW - ultrasound

U2 - 10.1007/s00421-015-3320-8

DO - 10.1007/s00421-015-3320-8

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VL - 116

SP - 611

EP - 621

JO - European Journal of Applied Physiology

JF - European Journal of Applied Physiology

SN - 1439-6319

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ER -