Effect of pillow size preference on extensor digitorum communis muscle strength and electromyographic activity during maximal contraction in healthy individuals: a pilot study.

BACKGROUND Cervical pillow height is an important factor that affects the perception of pillow comfort. However, few studies have addressed methods for predicting a patient's preferred cervical pillow size. We studied the effect of pillow size preference on the strength and electromyographic (EMG) signals of the upper extremity muscle. If the response of the upper extremity muscle is affected by pillow size preference, this would aid in devising an alternate strategy for selecting the optimal pillow size. METHODS Twenty-nine healthy individuals (mean age: 28.6 years, range: 24-55 years) participated in this study. The participants performed isometric maximal finger extension in the supine position with their heads supported on four different size preferences of cervical pillow (the most comfortable, next most comfortable, worst, and next worst). Maximal contraction force and peak-to-peak EMG amplitude of the extensor digitorum communis (EDC) during contraction were measured. One-way repeated-measures analysis of variance was used to evaluate the effect of pillow size preference. We also explored the relationship between anthropometric parameters and the individual's cervical pillow height preference. RESULTS The two most comfortable pillows were associated with significantly larger maximal EDC force than the two worst pillows. However, no significant differences in EMG were observed between pillows. No statistically significant correlation was found between anthropometric parameters and pillow height preference. CONCLUSION The results suggest that anatomical body measurements are not good predictors of optimal pillow height. As EDC muscle strength is affected by pillow height preference, maximal EDC muscle strength may be a useful complement for selecting the optimal pillow size.