Comparison of muscle activity during sit-to-stand movement at different chair heights between obese and normal-weight subjects.

The purpose of present study was to compare the tibialis anterior (TA), rectus femoris (RF), and erector spinae (ES) muscle activities at variety chair height during sit-to-stand (STS) on normal weight and obese subjects. Also, we compared the muscle activity difference between the normal weight and obese subjects. The study included 26 subjects (normal weight 13 and obese 13). Each subject performed STS at three chair heights (40 cm, 50 cm, 60 cm) and TA, RF, and ES muscle activities measured. According to the results of the measurement, muscle activation of TA showed significantly higher than RF and ES muscle activation during STS at all chair heights on obese subjects. The muscle activation of TA showed significantly higher than RF muscle activation during STS at all chair heights on normal weight subjects. The muscle activation of RF and ES showed significantly higher in normal weight subjects than obese subjects at 40 cm and 50 cm of chair heights. However, the TA muscle activation showed no significant difference between normal weight subjects and obese subjects. This study's results suggested that obese subjects should practice the use of RF and ES muscles in a low-height chair during STS.

Comparison of anterior gluteus medius fiber activation during general exercises and PNF exercises.

[Purpose] This study compared the activation of anterior gluteus medius fibers during general exercises and proprioceptive neuromuscular facilitation exercises. [Subjects and Methods] The study enrolled 15 healthy adults. The participants performed general hip abductor strengthening exercises and proprioceptive neuromuscular facilitation exercises; during both types of exercise, electromyography activity was recorded. [Results] Greater anterior gluteus medius fiber activation was observed during the proprioceptive neuromuscular facilitation exercises compared with the general hip abductor strengthening exercises. The anterior gluteus medius fibers exhibited greater activity during pattern 2 exercises compared with any other type of exercise. [Conclusion] The results suggest that pattern 2 exercises can selectively activate anterior gluteus medius fibers.

Electromyography activity of the deltoid muscle of the weight-bearing side during shoulder flexion in various weight-bearing positions.

[Purpose] This study investigated the deltoid muscle activation during shoulder flexion exercise in various weight-bearing positions. [Subjects] A total of 15 males participated. [Methods] The participants completed three repetitions of shoulder flexion exercises in three positions (prone-on-elbow, quadruped, and standing) with electromyography activity being collected from the exercised. The muscle activations in each position by each exercise were compared using a one-way analysis of variance. [Results] The electromyography activities of the middle and posterior deltoids differed significantly among positions. The prone-on-elbow and quadruped position showed a significantly higher activity than the standing position. There were no significant differences between the prone-on-elbow and quadruped positions. [Conclusion] The deltoid muscles were further strengthened in the low posture positions (prone-on-elbows and quadruped) than in standing.

The Effect of Somatosensory and Cognitive-motor Tasks on the Paretic Leg of Chronic Stroke Patients in the Standing Posture.

[Purpose] The purpose of this study was to investigate how different standing surfaces alter somatosensory input and how postural control is affected by these changes during the performance of a dual task with a cognitive-motor aspect. [Subjects] The subjects were 20 chronic stroke patients: 18 males, 2 females. [Methods] COP total distance, sway velocity, and the weight load on the paretic leg were measured while subjects performed the following three tasks (somatosensory task, cognitive-motor task, and dual task). [Results] Both COP total distance and sway velocity significantly decreased during the performance of all tasks. COP total distance and sway velocity significantly decreased during the somatosensory task and the dual task. The weight load significantly increased during performance of the somatosensory task and the dual task. [Conclusion] Compensatory mechanisms in the non-paretic leg were limited by placing it on an air cushion, and we observed an increase in somatosensory input from the paretic leg due to an enhanced weight load.