Effects of two types of pillows on bilateral sternocleidomastoid EMG activity in healthy subjects and in patients with myogenic cranio-cervical-mandibular dysfunction

Analysis of neck and back muscle activity during the application of various pillow designs in patients with forward head posture

BACKGROUND

There are currently no reports of biomechanical changes in patients with forward head posture (FHP) that result in altered muscle activation throughout various functions with muscle activation response during diverse sleep postures.

OBJECTIVE

This study investigated neck and back muscle activity in individuals with and without FHP during a maintained side-sleeping position by incorporating various pillow designs.

METHODS

Thirty-four participants (i.e., 17 in each group) were enrolled. The muscle activity was investigated via surface electromyography during the use of three trial pillows: orthopedic pillow, hollow pillow, and Thai neck support pillow.

RESULTS

With the application of all three trial pillow, the FHP group demonstrated significantly greater middle-lower trapezius muscle activity than the normal head posture group (p< 0.05). Sternocleidomastoid and upper trapezius (UT) muscle activity were similar between the two groups (p> 0.05). Only UT muscle activity was affected by variations in pillow design. In the normal group, no difference was observed in the muscle activity between all three pillows (p> 0.05).

CONCLUSIONS

Feasibly, the ability to appropriately modify a pillow configuration without creating undesired muscle activation was limited to those exhibiting FHP. Therefore, specially designed pillows or mattresses should be investigated in terms of their relevance to muscle fatigue and potential musculoskeletal pain in FHP patients.

Development and comparative evaluation of new shapes of pillows

The purpose of this study was to determine pillow designs suitable for supine and side-lying positions. [Subjects] Twenty female and twenty male subjects with a mean age of 22.7 years (SD = 1.3) participated in the study. [Methods] First, a three-dimensional motion analysis system was used to analyze the movements of the head and the shoulder joints during changes from supine positions to side-lying positions. Second, the height from the face to the shoulder and the height from the floor to the middle of the neck in a side-lying position were measured. Third, the weight distribution ratios of the head and the trunk were compared using general pillows (polyester sponge), memory foam, and prototype pillows. [Results] During position changes from supine positions to side-lying positions, the head moved in a fan shape, and the shoulder joint moved an average of 4.4 cm upward. The height from the face to the shoulder was 9 cm on average. The height from the floor to the middle of the neck was 11 cm on average. The weight distribution ratios between the head and the trunk were compared among general pillows (polyester sponge), memory foam, and prototype pillows. The results showed significant differences in the side-lying position. [Conclusion] Pillows with uniform heights are not suitable for a supine or side-lying position. In the case of both positions, users should be allowed to select pillows in shapes that can support the neck.

Shape design of an optimal comfortable pillow based on the analytic hierarchy process method

OBJECTIVE

Few studies have analyzed the shapes of pillows. The purpose of this study was to investigate the relationship between the pillow shape design and subjective comfort level for asymptomatic subjects.

METHODS

Four basic pillow designs factors were selected on the basis of literature review and recombined into 8 configurations for testing the rank of degrees of comfort. The data were analyzed by the analytic hierarchy process method to determine the most comfortable pillow.

RESULTS

Pillow number 4 was the most comfortable pillow in terms of head, neck, shoulder, height, and overall comfort. The design factors of pillow number 4 were using a combination of standard, cervical, and shoulder pillows. A prototype of this pillow was developed on the basis of the study results for designing future pillow shapes.

CONCLUSIONS

This study investigated the comfort level of particular users and redesign features of a pillow. A deconstruction analysis would simplify the process of determining the most comfortable pillow design and aid designers in designing pillows for groups.