Changes in the Linear Relationship between Muscle Contraction Intensity and Muscle Hardness after Rectus Femoris Muscle Strain
Objective. Joint torque differences between healthy and rehabilitated legs are often measured as a clinical index of recovery from muscle strain injury. Unfortunately, it should be noted that this is a questionable evaluation measure of the muscle after injury because it is a composite value includi...
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| Format: | Article |
| Language: | English |
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Wiley
2019-01-01
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| Series: | Case Reports in Orthopedics |
| Online Access: | http://dx.doi.org/10.1155/2019/7813217 |
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| _version_ | 1832566851054338048 |
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| author | Takayuki Inami Takuya Shimizu Tomoaki Osuga Takaya Narita Norikazu Hirose Mitsuyoshi Murayama |
| author_facet | Takayuki Inami Takuya Shimizu Tomoaki Osuga Takaya Narita Norikazu Hirose Mitsuyoshi Murayama |
| author_sort | Takayuki Inami |
| collection | DOAJ |
| description | Objective. Joint torque differences between healthy and rehabilitated legs are often measured as a clinical index of recovery from muscle strain injury. Unfortunately, it should be noted that this is a questionable evaluation measure of the muscle after injury because it is a composite value including related cooperating muscles. Meanwhile, the use of ultrasound elastography for the measurement of individual muscle mechanical properties (i.e., muscle hardness) has recently expanded. The purpose of this study was to examine, using ultrasound elastography, the differences in the linear relationship between muscle contraction intensity and muscle hardness during knee extension in athletes who had recovered from grade II rectus femoris muscle strain injury through comparison of the healthy and rehabilitated legs. Methods. Six athletes participated. Rectus femoris muscle hardness, determined during isometric contraction at 10%, 20%, 30%, and 40% of maximum voluntary contraction, was evaluated using ultrasound strain elastography. Results and Conclusion. The results indicated that for the healthy legs, the strain ratios, as indicated by muscle hardness, decreased linearly (became harder) with contraction intensity, but the strain ratios for the rehabilitated legs decreased nonlinearly. These results show the danger of judging the recovery period using only the difference between healthy and rehabilitated muscle strengths and the importance of evaluating individual muscles. |
| format | Article |
| id | doaj-art-b17e3e7128884c88a1702e5c42707469 |
| institution | Kabale University |
| issn | 2090-6749 2090-6757 |
| language | English |
| publishDate | 2019-01-01 |
| publisher | Wiley |
| record_format | Article |
| series | Case Reports in Orthopedics |
| spelling | doaj-art-b17e3e7128884c88a1702e5c427074692025-02-03T01:03:07ZengWileyCase Reports in Orthopedics2090-67492090-67572019-01-01201910.1155/2019/78132177813217Changes in the Linear Relationship between Muscle Contraction Intensity and Muscle Hardness after Rectus Femoris Muscle StrainTakayuki Inami0Takuya Shimizu1Tomoaki Osuga2Takaya Narita3Norikazu Hirose4Mitsuyoshi Murayama5Institute of Physical Education, Keio University, 4-1-1, Hiyoshi, Kanagawa 223-8521, JapanGraduate School of Health and Sport Sciences, Chukyo University, 101, Tokodate, Toyota City, Aichi 470-0348, JapanOsuga Clinic Orthopaedics, 117, Takegaya, Tokai City, Aichi 477-0032, JapanDepartment of Sports Technology, Toin University of Yokohama, 1614 Kurogane-cho, Aoba-ku, Yokohama, Kanagawa 225-8503, JapanFaculty of Sport Sciences, Waseda University, 2-7-5, Higashi-Fushimi, Tokyo 202-0021, JapanInstitute of Physical Education, Keio University, 4-1-1, Hiyoshi, Kanagawa 223-8521, JapanObjective. Joint torque differences between healthy and rehabilitated legs are often measured as a clinical index of recovery from muscle strain injury. Unfortunately, it should be noted that this is a questionable evaluation measure of the muscle after injury because it is a composite value including related cooperating muscles. Meanwhile, the use of ultrasound elastography for the measurement of individual muscle mechanical properties (i.e., muscle hardness) has recently expanded. The purpose of this study was to examine, using ultrasound elastography, the differences in the linear relationship between muscle contraction intensity and muscle hardness during knee extension in athletes who had recovered from grade II rectus femoris muscle strain injury through comparison of the healthy and rehabilitated legs. Methods. Six athletes participated. Rectus femoris muscle hardness, determined during isometric contraction at 10%, 20%, 30%, and 40% of maximum voluntary contraction, was evaluated using ultrasound strain elastography. Results and Conclusion. The results indicated that for the healthy legs, the strain ratios, as indicated by muscle hardness, decreased linearly (became harder) with contraction intensity, but the strain ratios for the rehabilitated legs decreased nonlinearly. These results show the danger of judging the recovery period using only the difference between healthy and rehabilitated muscle strengths and the importance of evaluating individual muscles.http://dx.doi.org/10.1155/2019/7813217 |
| spellingShingle | Takayuki Inami Takuya Shimizu Tomoaki Osuga Takaya Narita Norikazu Hirose Mitsuyoshi Murayama Changes in the Linear Relationship between Muscle Contraction Intensity and Muscle Hardness after Rectus Femoris Muscle Strain Case Reports in Orthopedics |
| title | Changes in the Linear Relationship between Muscle Contraction Intensity and Muscle Hardness after Rectus Femoris Muscle Strain |
| title_full | Changes in the Linear Relationship between Muscle Contraction Intensity and Muscle Hardness after Rectus Femoris Muscle Strain |
| title_fullStr | Changes in the Linear Relationship between Muscle Contraction Intensity and Muscle Hardness after Rectus Femoris Muscle Strain |
| title_full_unstemmed | Changes in the Linear Relationship between Muscle Contraction Intensity and Muscle Hardness after Rectus Femoris Muscle Strain |
| title_short | Changes in the Linear Relationship between Muscle Contraction Intensity and Muscle Hardness after Rectus Femoris Muscle Strain |
| title_sort | changes in the linear relationship between muscle contraction intensity and muscle hardness after rectus femoris muscle strain |
| url | http://dx.doi.org/10.1155/2019/7813217 |
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