Analysis of Vibration Frequency and Direction for Facilitating Upper-Limb Muscle Activity
Cheng-Hua Ni,
Yueh-Hsun Lu,
Li-Wei Chou,
Shu-Fen Kuo,
Chia-Huei Lin,
Shang-Lin Chiang,
Liang-Hsuan Lu,
Xin-Miao Wang,
Jia-Lan Chang,
Chueh-Ho Lin
Affiliations
Cheng-Hua Ni
Department of Nursing, Center for Nursing and Healthcare Research in Clinical Practice Application, Wan Fang Hospital, School of Nursing, College of Nursing, Taipei Medical University, Taipei 11031, Taiwan, R.O.C.
Yueh-Hsun Lu
Department of Radiology, Shuang-Ho Hospital, Taipei Medical University, New Taipei City 235041, Taiwan, R.O.C.
Li-Wei Chou
Department of Physical Therapy and Assistive Technology, National Yang Ming Chiao Tung University, Taipei 112304, Taiwan, R.O.C.
Shu-Fen Kuo
School of Nursing, College of Nursing, Taipei Medical University, Taipei 11031, Taiwan, R.O.C.
Chia-Huei Lin
Department of Nursing, Tri-Service General Hospital, School of Nursing, National Defense Medical Center, Taipei 114202, Taiwan, R.O.C.
Shang-Lin Chiang
Department of Physical Medicine and Rehabilitation, Tri-Service General Hospital, School of Medicine, National Defense Medical Center, Taipei 114202, Taiwan, R.O.C.
Liang-Hsuan Lu
Department of Physical Therapy and Assistive Technology, National Yang Ming Chiao Tung University, Taipei 112304, Taiwan, R.O.C.
Xin-Miao Wang
Faculty of Humanities, Zhejiang Dong Fang Polytechnic College, Wenzhou 325011, China
Jia-Lan Chang
Department of Physical Medicine and Rehabilitation, Shuang Ho Hospital, Taipei Medical University, Taipei 235041, Taiwan, R.O.C.
Chueh-Ho Lin
Master Program in Long-Term Care, College of Nursing, Taipei Medical University, Taipei 11031, Taiwan, R.O.C.
We aimed to determine the effect of vibration frequency and direction on upper-limb muscle activation using a handheld vibrator. We recruited 19 healthy participants who were instructed to hold a handheld vibrator in their dominant hand and maintain the elbow at 90° flexion, while vertical and horizontal vibrations were applied with frequencies of 15, 30, 45, and 60 Hz for 60 s each. Surface electromyography (EMG) measured the activities of the flexor digitorum superficialis (FDS), flexor carpi radialis (FCR), extensor carpi ulnaris (ECU), extensor carpi radialis (ECR), biceps, triceps, and deltoid anterior muscles. EMG changes were evaluated as the difference in muscle activity between vibration and no-vibration (0 Hz) conditions. Muscle activity was induced under vibration conditions in both vertical and horizontal (p < 0.05) directions. At 45 Hz, FDS and FCR activities increased during horizontal vibrations, compared with those during vertical vibrations. ECU activity significantly increased under 15-Hz vertical vibrations compared with that during horizontal vibrations. Vibrations from the handheld vibrator significantly induced upper-limb muscle activity. The maximum muscle activations for FDS, ECR, ECU, biceps, and triceps were induced by 45-Hz horizontal vibration. The 60-Hz vertical and 30-Hz horizontal vibrations facilitated maximum muscle activations for the FCR and deltoid anterior, respectively.
