Objectives This study compared foot arch height, plantar fascia thickness, a range of motion assessments of the ankle joint, strength of the ankle joint, plantar pressure, and balance between obese and normal weight young adults. Methods Fifty-two participants were required for the present study design to achieve 80% power, 0.8 effect size (η2), and an alpha level of 0.05. The participants were categorized to normal weight or obese groups based on BMI (≤ 24 kg/m 2 and ≥ 25 kg/m 2 , respectively). The foot and ankle disability index and Sport survey were completed by the participants before the measurements. Foot arch height was measured using the navicular drop test, and plantar fascia thickness was measured using ultrasound. Plantar pressure and balance tests were also conducted, followed by ankle joint range of motion and strength tests. Results Foot arch height and plantar fascia thickness was significantly higher in the obese group compared with the normal weight group ( p < 0.01). There were significant differences in eversion of ankle strength, plantar pressure in the big toe and heel and anterior-posterior balance between normal and obese weight groups ( p < 0.05). Conclusion Obese young adults had more abnormalities in the medial longitudinal arch, plantar fascia, and plantar pressure as well as weakened ankle eversion strength and balance problems compared with the normal weight group.

[Purpose] The aim of this study was to determine the appropriate pressure variation for performing a successful abdominal drawing-in maneuver (ADIM). The abdominal muscle thickness variations and contraction ratios were examined in relation to pressure variations using a Pressure Biofeedback Unit (PBU) during an ADIM in the supine position. [Methods] The PBU was placed identically between the lumbar lordosis of 20 healthy subjects (12 males and 8 females) and the pressure of the PBU was maintained at 40 mmHg. Then, while the subjects performed ADIM at four random pressure variations (0, 2, 4, or 6 mmHg), the thicknesses of the transversus abdominis (TrA), the internal oblique abdominal muscle (IO), and the external oblique abdominal muscle (EO) were measured using ultrasonography. [Results] Pressure increases of 0–2 mmHg resulted in significant decreases in IO and EO thicknesses compared to pressure increases of 6 mmHg. Increases of 0–2 mmHg also resulted in significant decreases in IO+EO and EO contraction ratios compared to pressure increases of 6 mmHg, while the preferential activation ratio of the TrA was significantly increased. [Conclusion] Compared to the other pressure increases, an increase of 0–2 mmHg effectively regulated the thicknesses and contraction ratios of superficial muscles such as IO and EO, rather than the thickness and contraction ratio of the TrA, showing high and indirect preferential activation ratios for TrA. Therefore, for successful ADIM, rather than using large PBU pressure increases, exercises that promote slight increases of around 0–2 mmHg from a baseline of 40 mmHg are desirable.

Abstract. [Purpose] This study was conducted to investigate the effects of rehabilitative ultrasound imaging (RUSI) feedback during the abdominal hollowing exercise (AHE) in three different positions by monitoring the changes in the thicknesses of the abdominal muscles.[Subjects] The subjects of this study were 42 healthy male adults who listened to an explanation of the study method and purpose and agreed to participate in the experiments. They were divided into an experimental group of 21 subjects who received RUSI feedback and a control group of 21 subjects who did not receive RUSI feedback.[Methods] The thickness of the abdominal muscles was measured during rest and AHE in three positions. The thickness changes between rest and AHE were compared between the two groups.[Results] The difference in internal abdominal oblique (IO) thickness changes between the groups were significant. The differences in external abdominal oblique (EO) thickness changes were only significant among the positions. A post hoc analysis of the differences in EO thickness changes among the positions found significant differences between the crook lying and four-point kneeling positions. The transversus abdominis (TrA) thickness changes showed significant interaction between group and position. [Conclusion] RUSI feedback assists the independent activities of TrA by decreasing the thickness changes of global muscles such as IO and EO. Furthermore, crook lying is a more effective position in AH training with RUSI feedback than the other two positions as it increases TrA thickness changes while minimizing those of EO.

This study investigated potential for foot dysfunction and plantar fasciitis according to the shape of the foot arch in young adults. Fifty-two participants were required for the present study design to achieve 80% power, 0.8 effect size (η2), and an alpha level of 0.05. This study recruited 52 young adults (30 men and 22 women). All participants voluntarily agreed to participate in the study after hearing explanations about the purpose and process of the study. They were divided into two groups of 26 according to the shape of foot with and without flat foot using the navicular drop test. The participants were measured the foot function index (FFI), range of motion (ROM) of ankle, and four-way ankle strength. Additionally, the thickness of the plantar fascia was measured using ultrasonography. Intraclass correlation coefficient (ICC) was used to verify the inter- and intrarater reliability of ultrasonography. The inter- and intrarater reliability was excellent (ICC2,1=0.88, ICC3,1=0.93). There were significant differences in dorsi-flexion of ankle ROM, FFI, dorsi-flexion and eversion of ankle strength, and the thickness of the plantar fascia between the two groups (P<0.05). Based on the results, the group with flat foot may gradually generate potential of the foot dysfunction and plantar fasciitis. Therefore, the interventions are necessary to improve the foot dysfunction and plantar fasciitis in people with flat foot.

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