The purpose of this study was to investigate the effects of stimulation conditions (pressing force and frequency) and subcutaneous tissue properties (thickness and hardness) on the changes in tendon blood circulation caused by acupressure. Before and after acupressure, blood circulation of the Achilles tendon was measured using red laser lights. Acupressure was applied to the Achilles tendon for 3-min under three conditions. The following four conditions (including no stimulation condition) with different combinations of pressing forces and frequencies were established: 1) 50N and 1.5Hz, 2) 25N and 3.0Hz, 3) 25N and 1.5Hz, and 4) no stimulation. In addition, the thickness and hardness of subcutaneous tissue at the acupressure-stimulated site were measured. The change in total hemoglobin (corresponding to blood volume) showed a significant main effect of condition, but the effects of time and the interaction between conditions and time were not significant. On average, the most significant increase in tendon blood volume was observed in the 50N and 1.5Hz condition, although the post-hoc test showed no significant difference. The subcutaneous tissue thickness and hardness were not significantly correlated with tendon blood volume changes after stimulation in any of the three conditions. In conclusion, the present results indicate that acupressure under the conditions of pressing force 50N and frequency 1.5Hz changed tendon blood circulation the most, though not based on exact statistical results. Furthermore, the subcutaneous tissue thickness and hardness (including tendon) have no effect on tendon blood circulation induced by stimulation.

Pelvic floor muscle (PFM) exercises have been shown to strengthen PFM function and improve urinary incontinence (UI) symptoms. Several studies have focused on voluntary PFM activity changes among various supine postures. However, few studies have investigated standing postures that promote PFM contraction. Since patients often complain of UI symptoms in the standing position, knowing which posture during voluntary PFM contraction in the standing position promotes contraction would be useful from the viewpoint of issuing exercise instructions and improving prevention. This study aimed to investigate adequate standing postures for PFM contraction and included nine healthy women. All participants performed maximum voluntary contraction (MVC) of PFM in six standing postures: neutral, abduction, adduction, neutral-external rotation, abduction-external rotation, and adduction-external rotation. The MVC of PFM, adductor magnus muscle, and internal oblique muscles were measured in each posture, and muscle activities were recorded using surface electromyography. We compared muscle activity, with and without hip joint external rotation, in the neutral, abduction, and adduction positions, and looked for increased muscle activity of PFM in standing postures with hip joint external rotation compared to standing positions without hip joint external rotation (p < 0.01). Since PFM contracts in conjunction with hip adductors and external rotators, the activity of PFM may have been higher in the standing posture with hip external rotation. Selecting the effective posture is important to increase PFM activity.

We tested a hypothesis that individuals with low maximal voluntary isometric contraction relative to muscle cross-sectional area (MVC/mCSA) would have greater strength gain compared to those with high MVC/mCSA in an early stage from beginning of isometric training to volitional failure. Male adults (n = 24; 22.4 ± 2.5 years, 174.1 ± 6.5 cm, 75.8 ± 14.1 kg) conducted a 3-week isometric training to volitional failure (60-80% MVC, 2-3 times/week, 3 sets/session) in elbow joint flexion with 90° flexion of each arm. Based on the relationship between MVC and mCSA before the intervention, we assigned 16 arms to the higher group (HIGH), 14 to the lower group (LOW) and 18 to the mean group (MEAN). Before the intervention and at the beginning of every week, we measured MVC (myometer) and muscle thickness of anterior upper arm (ultrasound). The mCSA was derived from muscle thickness. The 3-week isometric training to volitional failure increased MVC in all groups, but the relative change in MVC through the intervention was higher in LOW than in HIGH and MEAN groups. The current findings of this study support the abovementioned hypothesis.