BACKGROUND Computer users are exposed to work related neck disorders due to repetitive movement and static posture for prolonged period. Viewing document and typing simultaneously are one of the contributing factors for neck disorders. METHODS This preliminary study was conducted to evaluate the effects of the document holder on the postural neck muscles activity among computer users. Nine he...

[Purpose] The purpose of this study was to measure the cervical flexion-relaxation ratio (FRR) and intensity of neck pain and identify the differences according to postures adopted while using smartphones. [Subjects] Fifteen healthy adults with no neck pain, spinal trauma, or history cervical surgery participated in this study. [Methods] The activity of the cervical erector spinae muscle was re...

OBJECTIVES To compare the effects of biofeedback with those of active exercise and passive treatment in treating work-related neck and shoulder pain. DESIGN A randomized controlled trial with 3 intervention groups and a control group. SETTING Participants were recruited from outpatient physiotherapy clinics and a local hospital. PARTICIPANTS All participants reported consistent neck and s...

Control of head position during postural responses is important to facilitate both the interpretation of vestibular signals and the stabilization of gaze. In these experiments, we compared head stabilization for two different postural tasks: 1) in response to perturbations at the head, and 2) in response to perturbations induced at the support surface, which perturb both body and head position....

Whiplash injuries are the most common injuries following rear-end collisions. During a rear-end collision, the human muscle response consists of both a postural and a startle response that may exacerbate injury. However, most previous studies only assessed the presence of startle using data collected from the neck muscles and head/neck kinematics. The startle response also evokes a descending p...

The topography of the cortical motor projection to the sternocleidomastoid (SCM) muscles was investigated in 15 normal subjects using the technique of transcranial magnetic stimulation. Contrary to the long-held view that the representation of the neck muscles in the motor strip is close to that of the face, our findings indicate that the projection to both the ipsilateral and contralateral SCM...

Work related musculoskeletal disorders (WMSDs) in the shoulder/neck area and the upper extremities are a common problem among computer operators, especially women. A frequent type of WMSDs in the shoulder/neck area, which also may exist in the upper extremities, is chronic muscle pain (myalgia). The mechanisms for the development (etiology) of myalgia in the shoulder/neck area and in the upper ...

This review article deals with some effects of neck muscle proprioception on human balance, gait trajectory, subjective straight-ahead (SSA), and self-motion perception. These effects are easily observed during neck muscle vibration, a strong stimulus for the spindle primary afferent fibers. We first remind the early findings on human balance, gait trajectory, SSA, induced by limb, and neck mus...