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Cross-sectional area and muscle activity of the lumbar multifidus muscles in varying postures during abdominal draw-in exercises
WCPT Congress 2015 / Physiotherapy 2015; Volume 101, Supplement 1 eS1238–eS1642
Research Report Poster Presentation Number: RR-PO-04-23-Sat Saturday 2 May 2015 12:15 Exhibit halls 401–403 CROSS-SECTIONAL AREA AND MUSCLE ACTIVITY OF THE LUMBAR MULTIFIDUS MUSCLES IN VARYING POSTURES DURING ABDOMINAL DRAW-IN EXERCISES M. Watanabe 1 , T. Hayashi 1 , Y. Miyazaki 1 , S. Miyakawa 2 1 Tsukuba
International University, Physical Therapy, Ibaraki, Japan; 2 University of Tsukuba, Graduate School of Comprehensive Human Sciences, Ibaraki, Japan Background: In the prevention of low back pain, the selective training of deep muscles such as the transverse abdominal (TrA) and multifidus (MF) muscles is an important initial stage. Co-contraction of the TrA and MF muscles is important for trunk stability. Therefore, physical therapists train patients to selectively contract the TrA muscles using abdominal draw-in exercises, but studies have shown that TrA muscle activity during draw-in exercises is not affected by posture. To the best of our knowledge, only few studies have reported the correlation between posture and maximum muscle activity during draw-in exercises, but no studies have examined MF muscle activity during draw-in exercises. Purpose: This study was designed to clarify the MF muscle activity during the draw-in exercise performed in four different postures. Differences in muscle activity and crosssectional area among postures were measured using surface electrodes and ultrasonography. Methods: Eleven men (24 ± 2 years) assumed four postures in which they performed the draw-in exercises: sitting pelvic neutral (S-N); sitting pelvic anterior tilt (S-A); sitting pelvic posterior tilt (S-P); and standing position. The MF muscle activity was measured using surface electrodes. To normalize muscle activity, the maximum voluntary contraction (MVC) was measured on both sides, and the root mean square was calculated to determine the muscle activity in each posture. At the same time, using ultrasonography, still images of the MF muscle in the line of the fourth lumbar spinous process were recorded. The cross-sectional area was measured in 0.1-mm units. To compare the muscle activities and crosssectional areas among postures, one-way repeated measures analysis of variance was used. Results: MF muscle activity was significantly higher in the S-A posture (Rt. 24.6% MVC, Lt. 21.3% MVC, p < 0.05) than in the other postures. Furthermore, MF muscle activity was significantly higher in the standing posture than in the S-P posture. No differences in the cross-sectional areas of the MF muscle were seen among postures. Conclusion(s): In this study, draw-in exercises were performed by patients in four different postures to selectively
eS1609
contract the TrA muscle. We found higher MF muscle cocontraction in the standing and S-A postures. However, no changes were seen in the cross-sectional area. Earlier studies have shown that the sacroiliac joint was stabilized by the simultaneous contraction of TrA and MF muscles. The current findings suggest that draw-in exercises in the S-A and standing postures could effectively increase MF muscle activity and consequently trunk stability since cocontraction of the MF and TrA muscles contributes to trunk stability. Visual feedback on the changes in muscle activity during exercise could increase effectiveness; however, in our study, change in MF muscle activity could not be captured by ultrasonography. Hence, imaging modalities that provide visual depiction of muscle activity change are needed. Implications: This study showed clear differences in muscle activity in different postures during exercise involving contraction of the TrA and co-contraction of the MF. These findings could serve as a reference to ensure effective training. Keywords: Electromyography; Ultrasonography; Low back pain Funding acknowledgements: The authors have declared no conflicts of interest. Ethics approval: This study was approved by the ethics committee of the Tsukuba University of Technology. http://dx.doi.org/10.1016/j.physio.2015.03.1622 Research Report Poster Presentation Number: RR-PO-04-07-Sun Sunday 3 May 2015 12:15 Exhibit halls 401–403 HISTOPATHOLOGICAL CHANGES IN JOINT COMPONENTS IN A RAT KNEE JOINT CONTRACTURE MODEL FOLLOWING LOW-INTENSITY PULSED ULTRASOUND M. Watanabe 1 , S. Kojima 2 , M. Hoso 3 1 Nagoya
Gakuin University, Department of Physical Therapy, Faculty of Rehabilitation Science, Seto, Japan; 2 Kinjo University, Department of Physical Therapy, Faculty of Rehabilitation Sciences, Hakusan, Japan; 3 Kanazawa University, Division of Health Sciences, Graduate School of Medical Science, Kanazawa, Japan Background: Ultrasound is sometimes used for its hyperthermic effects in Electrophysical Agents (EPA) for contracture. However, the effects of vibratory stimulation that does not produce hyperthermic action on contracture remain unclear. Low-intensity pulsed ultrasound (LIPUS) not only promotes bone healing, but has also been reported as effective for injuries of soft tissue such as muscles, tendons and ligaments and affects collagen dynamics. However, no reports have investigated its effects on the joint capsule, which remain unclear.
Research Report Poster Presentation Number: RR-PO-04-23-Sat Saturday 2 May 2015 12:15 Exhibit halls 401–403 CROSS-SECTIONAL AREA AND MUSCLE ACTIVITY OF THE LUMBAR MULTIFIDUS MUSCLES IN VARYING POSTURES DURING ABDOMINAL DRAW-IN EXERCISES M. Watanabe 1 , T. Hayashi 1 , Y. Miyazaki 1 , S. Miyakawa 2 1 Tsukuba
International University, Physical Therapy, Ibaraki, Japan; 2 University of Tsukuba, Graduate School of Comprehensive Human Sciences, Ibaraki, Japan Background: In the prevention of low back pain, the selective training of deep muscles such as the transverse abdominal (TrA) and multifidus (MF) muscles is an important initial stage. Co-contraction of the TrA and MF muscles is important for trunk stability. Therefore, physical therapists train patients to selectively contract the TrA muscles using abdominal draw-in exercises, but studies have shown that TrA muscle activity during draw-in exercises is not affected by posture. To the best of our knowledge, only few studies have reported the correlation between posture and maximum muscle activity during draw-in exercises, but no studies have examined MF muscle activity during draw-in exercises. Purpose: This study was designed to clarify the MF muscle activity during the draw-in exercise performed in four different postures. Differences in muscle activity and crosssectional area among postures were measured using surface electrodes and ultrasonography. Methods: Eleven men (24 ± 2 years) assumed four postures in which they performed the draw-in exercises: sitting pelvic neutral (S-N); sitting pelvic anterior tilt (S-A); sitting pelvic posterior tilt (S-P); and standing position. The MF muscle activity was measured using surface electrodes. To normalize muscle activity, the maximum voluntary contraction (MVC) was measured on both sides, and the root mean square was calculated to determine the muscle activity in each posture. At the same time, using ultrasonography, still images of the MF muscle in the line of the fourth lumbar spinous process were recorded. The cross-sectional area was measured in 0.1-mm units. To compare the muscle activities and crosssectional areas among postures, one-way repeated measures analysis of variance was used. Results: MF muscle activity was significantly higher in the S-A posture (Rt. 24.6% MVC, Lt. 21.3% MVC, p < 0.05) than in the other postures. Furthermore, MF muscle activity was significantly higher in the standing posture than in the S-P posture. No differences in the cross-sectional areas of the MF muscle were seen among postures. Conclusion(s): In this study, draw-in exercises were performed by patients in four different postures to selectively
eS1609
contract the TrA muscle. We found higher MF muscle cocontraction in the standing and S-A postures. However, no changes were seen in the cross-sectional area. Earlier studies have shown that the sacroiliac joint was stabilized by the simultaneous contraction of TrA and MF muscles. The current findings suggest that draw-in exercises in the S-A and standing postures could effectively increase MF muscle activity and consequently trunk stability since cocontraction of the MF and TrA muscles contributes to trunk stability. Visual feedback on the changes in muscle activity during exercise could increase effectiveness; however, in our study, change in MF muscle activity could not be captured by ultrasonography. Hence, imaging modalities that provide visual depiction of muscle activity change are needed. Implications: This study showed clear differences in muscle activity in different postures during exercise involving contraction of the TrA and co-contraction of the MF. These findings could serve as a reference to ensure effective training. Keywords: Electromyography; Ultrasonography; Low back pain Funding acknowledgements: The authors have declared no conflicts of interest. Ethics approval: This study was approved by the ethics committee of the Tsukuba University of Technology. http://dx.doi.org/10.1016/j.physio.2015.03.1622 Research Report Poster Presentation Number: RR-PO-04-07-Sun Sunday 3 May 2015 12:15 Exhibit halls 401–403 HISTOPATHOLOGICAL CHANGES IN JOINT COMPONENTS IN A RAT KNEE JOINT CONTRACTURE MODEL FOLLOWING LOW-INTENSITY PULSED ULTRASOUND M. Watanabe 1 , S. Kojima 2 , M. Hoso 3 1 Nagoya
Gakuin University, Department of Physical Therapy, Faculty of Rehabilitation Science, Seto, Japan; 2 Kinjo University, Department of Physical Therapy, Faculty of Rehabilitation Sciences, Hakusan, Japan; 3 Kanazawa University, Division of Health Sciences, Graduate School of Medical Science, Kanazawa, Japan Background: Ultrasound is sometimes used for its hyperthermic effects in Electrophysical Agents (EPA) for contracture. However, the effects of vibratory stimulation that does not produce hyperthermic action on contracture remain unclear. Low-intensity pulsed ultrasound (LIPUS) not only promotes bone healing, but has also been reported as effective for injuries of soft tissue such as muscles, tendons and ligaments and affects collagen dynamics. However, no reports have investigated its effects on the joint capsule, which remain unclear.