Comparison of Muscle Activity and Muscle Thickness According to Knee Flexion Angle during Supine Bridge Exercises using the Abdominal Drawing-in Maneuver on an Unstable Surface.

This study evaluated changes in deep trunk muscle thickness and lower extremity muscle activities during bridge exercises with the abdominal drawing-in maneuver. Bridge exercises were conducted on an unstable surface at different knee flexion angles (60º, 90º and 120º), with the aim of identifying more effective angles for bridge exercises. This study included 21 healthy adults, aged 20-27 years. Biceps femoris (BF), rectus abdominis, and rectus femoris activity was measured using surface electromyography. The thicknesses of the transverse abdominis (TrA), external oblique (EO) and internal oblique (IO) muscles were measured. BF (p = 0.000, partial η2 = 0.670) activity increased considerably as the knee flexion angle decreased. TrA (p = 0.000, partial η2 = 0.883) and IO (p = 0.000, partial η2 = 0.892) thickness significantly increased, while EO (p = 0.000, partial η2 = 0.893) thickness decreased as the knee flexion angle decreased. When performing bridge exercises using the abdominal drawing-in maneuver on an unstable surface, the knee flexion angles should be at 120º and 60º to increase trunk stability and lower extremity muscle activity, respectively.

Effects of the Computer Desk Level on the Musculoskeletal Discomfort of Neck and Upper Extremities and EMG Activities in Patients with Spinal Cord Injuries.

BACKGROUND: Computers are used as a means of social communication, for work and other purposes. However, patients with spinal cord injuries may have a higher risk than normal individuals with musculoskeletal problems when using computers owing to their inability to control respective postures due to problems in motor and sensory functioning. OBJECTIVES: This study is aimed at identifying the effect of computer desk heights on musculoskeletal discomforts of the neck and upper extremities and EMG activities in patients with spinal cord (C6) and upper thoracic spinal cord injuries. METHODS: Participants of the present study were the patients diagnosed with ASIA A or B. The patients were divided into two groups according to their spinal cord injuries: C6 group and T2-T6 group. The level of the desk was set at 5 cm below the elbow, at the elbow level, and 5 cm above the elbow level. Electromyography was used to measure the duration of typing task EMG(%RVC) of the cervical erector spinae, upper trapezius, anterior deltoid, and wrist extensor. Subjective musculoskeletal discomfort (Borg-RPE) was measured at the end of the experiment. RESULTS: The two groups showed differences in terms of RPE corresponding to each level of the computer desk (p < .05). Postanalysis revealed the C6 group had decreased RPE as the level of computer desk increased, whereas the subjects in the T2-T6 group had decreased RPE values in accordance with the decreasing level of computer desk (p < .05). In EMG, both groups had no significant differences (p > .05). However, in terms of the interaction between the muscles and the level of computer desk in both groups, the differences in the interactions of the upper trapezius and wrist extensor with each level of the desk were found (p < .05). CONCLUSION: This study is meaningful in that it confirms computer work posture and preference of spinal cord-injured individuals.

What is a more effective method of cranio-cervical flexion exercises?

BACKGROUND: Cranio-cervical flexion exercise (CCFE) is a representative exercise that activates the deep muscles of neck pain patients. However, there is a lack of studies that propose specific exercise methods to examine the more effective activity level of the deep cervical flexor. OBJECTIVE: The objective of this study is to propose a more effective exercise method through effect comparison based on an optimal degree of mouth-opening, a mouth-open versus mouth-closed position, eye gaze, and body position change during CCFE. METHODS: As a result of examining the optimal degree of mouth-opening during CCFE using a pressure biofeedback unit with 50 subjects conforming to a selection standard, sternocleidomastoid muscle activity was examined. An optimal degree of mouth-opening during CCFE was examined as well. In addition, muscle thickness and muscle activity were measured based on eye gaze. Then, the effect of the exercise based on body position was examined. RESULTS: The lowest sternocleidomastoid activity was presented at a mouth-opening of 20 mm. A significant difference was presented in sternocleidomastoid and longus colli muscle activity at a mouth-opening of (p< 0.05). The eye gaze of 45∘ below presented the lowest sternocleidomastoid activity. CONCLUSIONS: The results suggest a new type of exercise method with the accompaniment of an optimal degree of mouth-opening of (20 mm), along with an eye gaze of 45∘ below, and an exercise method in the seated position without spatial restriction in order to increase the effect of CCFE, one of the conventional neck stabilization exercise methods.

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.