This study investigated the effects of head postural correction on muscle activity during shoulder flexion and abduction. Twenty-four male participants with forward head posture (FHP) and no history of neurological or musculoskeletal surgery or injury...
This study investigated the effects of head postural correction on muscle activity during shoulder flexion and abduction. Twenty-four male participants with forward head posture (FHP) and no history of neurological or musculoskeletal surgery or injury were recruited.
Their muscle activity was analyzed before and after head correction during shoulder abduc tion and flexion. Muscle activity and onset time were assessed using wireless surface elec tromyography of the right splenius capitis (SC); sternocleidomastoid (SCM); upper, middle, and lower trapezius (UT, MT, LT); and serratus anterior (SA) during shoulder movement.
Shoulder abduction and flexion in FHP and neutral head posture (NHP) were compared us ing a paired t-test, and the main effects and interactions of head posture and shoulder movements were determined using a 2 × 2 repeated-measures analysis of variance using head posture and shoulder movements. When comparing shoulder abduction and flexion in the FHP, the muscle activities of the SCM and MT were significantly increased in abduc tion (p<.05). Muscle activity in all muscles except the SC and SA was significantly lower in NHP than in FHP inboth abduction and flexion (p>.05). Muscle onset time did not sig nificantly differ between the FHP and NHP groups (p>.05). However, the MT moved first in abduction in the FHP and NHP, UT in flexion in the FHP, and SA in the NHP. In this study, the muscle activity differed during abduction and flexion in the FHP. Therefore, arm movement may be useful in clinical practice to improve FHP symptoms, and these research results may be used as basic data for FHP.