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Resting muscle stiffness measured with ultrasound shear-wave elastography after static stretching
WCPT Congress 2015 / Physiotherapy 2015; Volume 101, Supplement 1 eS1238–eS1642
(P > 0.05), but the three-grade rehabilitation practice mode group had higher mean score than control group, and the students’ enthusiasm, ability to solve practical clinical problems were improved significantly. Conclusion(s): The students could benefit more from the three-grade practice mode when comparing single setting mode. And they were more interested and motivated in the three-grade practice mode. Implications: The students could perform better in different work setting. The practice mode could be applied in other course to perfect students’ practice skill. Keywords: Practice mode; Pediatric physical therapy; Acute-subacute-chronic Funding acknowledgements: Education funding of Kunming Medical University in China. Ethics approval: Ethical approval obtained from the 2nd affiliated hospital of Kunming Medical University. http://dx.doi.org/10.1016/j.physio.2015.03.1464 Research Report Poster Presentation Number: RR-PO-04-21-Mon Monday 4 May 2015 12:15 Exhibit halls 401–403 RESTING MUSCLE STIFFNESS MEASURED WITH ULTRASOUND SHEAR-WAVE ELASTOGRAPHY AFTER STATIC STRETCHING K. Taniguchi, S. Nozaki, M. Katayose Sapporo Medical University, Department of Physical Therapy, Sapporo, Japan Background: Various lower limb disorders are related to increased stiffness of the calf muscle and reduced dorsiflexion of the ankle. In an attempt to reduce the symptoms of such disorders, stretching exercises of the calf muscles are commonly prescribed to increase the available dorsiflexion range of the ankle joint. The effects of stretching on the magnitude and duration of acute changes in the stiffness of gastrocnemius muscle and their association with joint flexibility are unknown. Recently developed ultrasound shear-wave elastography has opened the possibility for objectively quantifying the stiffness of muscle belly in vivo (Shinohara et al., 2010). Purpose: The purpose of the study was to examine the acute effect of static stretching on the resting stiffness of gastrocnemius muscle belly in the longitudinal direction, and to determine the association between joint flexibility and muscle stiffness, using the ultrasound shear-wave elastography. Methods: Ten healthy young adults in the experimental group performed standing wall stretching that consisted of dorsiflexion to the participants’ volitional end range of motion (ROM) and holding the position for 5 min with brief breaks every minute. Ten additional healthy subjects in the
eS1489
comparison group performed a 5-min standing intervention without static stretching. Longitudinal ultrasonic images of the resting medial and lateral gastrocnemius heads were obtained at 30% proximal of the right lower leg length in the prone position with the neutral ankle angle and knee full extension. From these images, muscle stiffness was assessed as shear modulus before, immediately after, and at 5, 10, 15 and 20 min after stretching using the ultrasound shear-wave elastography. Results: In the experimental group, immediately after stretching, shear modulus decreased (P < 0.01) by 1.2 kPa (14.2%) compared with pre-stretching across muscle heads. The shear modulus returned to the pre-stretching value (P = 0.15) at 20 min after stretching. The dorsiflexion ROM increased (P < 0.01) by 3.9 deg (30.7%) immediately after stretching and returned (P = 0.35) in 20 min. In the comparison group, the standing intervention without stretching had no influence on these measures. There was a negative correlation (r = −0.67 to −0.74, all P < 0.05) between dorsiflexion ROM and shear modulus in either head before and after stretching. Conclusion(s): The results demonstrate the transient decreases in the stiffness of the resting gastrocnemius muscle belly after static stretching and indicate that joint flexibility is greater in individuals with lower resting stiffness of the muscle belly. Implications: The ultrasound shear-wave elastography technique is a technology that provides novel insights into the monitoring and investigation of muscular responses to stretching. The current findings serve as a foundation for exploring the use of muscle shear modulus as clinically relevant information for assessing the severity of musculoskeletal disorders and potential improvements due to various treatments. Keywords: Muscle elasticity; Shear modulus; Joint flexibility Funding acknowledgements: This work was supported by Grant-in-Aid for Young Scientists from the Ministry of Education, Culture, Sports, Science and Technology Grant. Ethics approval: The study was approved by the Medical Research Ethics Committee at Sapporo Medical University. http://dx.doi.org/10.1016/j.physio.2015.03.1465
(P > 0.05), but the three-grade rehabilitation practice mode group had higher mean score than control group, and the students’ enthusiasm, ability to solve practical clinical problems were improved significantly. Conclusion(s): The students could benefit more from the three-grade practice mode when comparing single setting mode. And they were more interested and motivated in the three-grade practice mode. Implications: The students could perform better in different work setting. The practice mode could be applied in other course to perfect students’ practice skill. Keywords: Practice mode; Pediatric physical therapy; Acute-subacute-chronic Funding acknowledgements: Education funding of Kunming Medical University in China. Ethics approval: Ethical approval obtained from the 2nd affiliated hospital of Kunming Medical University. http://dx.doi.org/10.1016/j.physio.2015.03.1464 Research Report Poster Presentation Number: RR-PO-04-21-Mon Monday 4 May 2015 12:15 Exhibit halls 401–403 RESTING MUSCLE STIFFNESS MEASURED WITH ULTRASOUND SHEAR-WAVE ELASTOGRAPHY AFTER STATIC STRETCHING K. Taniguchi, S. Nozaki, M. Katayose Sapporo Medical University, Department of Physical Therapy, Sapporo, Japan Background: Various lower limb disorders are related to increased stiffness of the calf muscle and reduced dorsiflexion of the ankle. In an attempt to reduce the symptoms of such disorders, stretching exercises of the calf muscles are commonly prescribed to increase the available dorsiflexion range of the ankle joint. The effects of stretching on the magnitude and duration of acute changes in the stiffness of gastrocnemius muscle and their association with joint flexibility are unknown. Recently developed ultrasound shear-wave elastography has opened the possibility for objectively quantifying the stiffness of muscle belly in vivo (Shinohara et al., 2010). Purpose: The purpose of the study was to examine the acute effect of static stretching on the resting stiffness of gastrocnemius muscle belly in the longitudinal direction, and to determine the association between joint flexibility and muscle stiffness, using the ultrasound shear-wave elastography. Methods: Ten healthy young adults in the experimental group performed standing wall stretching that consisted of dorsiflexion to the participants’ volitional end range of motion (ROM) and holding the position for 5 min with brief breaks every minute. Ten additional healthy subjects in the
eS1489
comparison group performed a 5-min standing intervention without static stretching. Longitudinal ultrasonic images of the resting medial and lateral gastrocnemius heads were obtained at 30% proximal of the right lower leg length in the prone position with the neutral ankle angle and knee full extension. From these images, muscle stiffness was assessed as shear modulus before, immediately after, and at 5, 10, 15 and 20 min after stretching using the ultrasound shear-wave elastography. Results: In the experimental group, immediately after stretching, shear modulus decreased (P < 0.01) by 1.2 kPa (14.2%) compared with pre-stretching across muscle heads. The shear modulus returned to the pre-stretching value (P = 0.15) at 20 min after stretching. The dorsiflexion ROM increased (P < 0.01) by 3.9 deg (30.7%) immediately after stretching and returned (P = 0.35) in 20 min. In the comparison group, the standing intervention without stretching had no influence on these measures. There was a negative correlation (r = −0.67 to −0.74, all P < 0.05) between dorsiflexion ROM and shear modulus in either head before and after stretching. Conclusion(s): The results demonstrate the transient decreases in the stiffness of the resting gastrocnemius muscle belly after static stretching and indicate that joint flexibility is greater in individuals with lower resting stiffness of the muscle belly. Implications: The ultrasound shear-wave elastography technique is a technology that provides novel insights into the monitoring and investigation of muscular responses to stretching. The current findings serve as a foundation for exploring the use of muscle shear modulus as clinically relevant information for assessing the severity of musculoskeletal disorders and potential improvements due to various treatments. Keywords: Muscle elasticity; Shear modulus; Joint flexibility Funding acknowledgements: This work was supported by Grant-in-Aid for Young Scientists from the Ministry of Education, Culture, Sports, Science and Technology Grant. Ethics approval: The study was approved by the Medical Research Ethics Committee at Sapporo Medical University. http://dx.doi.org/10.1016/j.physio.2015.03.1465