Purpose: The purpose of this study was to examine the effect of the location of spinal deformity on postural control during quiet standing in adolescent idiopathic scoliosis (AIS) by comparing the parameters of center of pressure (COP) between patients mainly with thoracic deformity (thoracic group) and those with lumbar deformity (lumbar group). Methods: This study included 100 patients with AIS (67 in the thoracic group and 33 in the lumbar group, mean age: 18.1 ± 5.5 years). We evaluated postural sway by measuring COP during quiet standing, and compared the indices of COP between the two groups. In each group, we also examined the relations of postural sway with age and radiographic parameters. Results: There was no significant difference in the COP parameters of sway between the two groups. However, the COP parameters of sway correlated with age in the thoracic group. In the lumbar group, the parameters of sway with eyes closed correlated with the Cobb angle. The effect of visual deprivation on length and area of COP was smaller in the lumbar group compared with the thoracic group. In both groups, there was a correlation between the lateral displacement of COP and coronal balance. Conclusion: The postural sway showed some different characteristics according to the location of spinal deformity. In the lumbar group, the postural sway was affected by the degree of spinal deformity.

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Purpose: The objective of the present study was to investigate differences in electromyography (EMG)-recorded amplitude and onset time between individuals with and without chronic nonspecific low back pain (LBP) during trunk rotation. Methods: Fifteen patients with LBP (9 men and 6 women; 22.5 ± 2.4 years) and 15 healthy control subjects (9 men and 6 women; 25.2 ± 5.5 years) participated in this study. Each subject was instructed to perform trunk rotation as fast as possible after a LED indicator signal. The amplitude and onset time in the onset phase of trunk rotation were recorded using surface EMG and a three-dimensional analysis system from three pairs of abdominal muscles and five pairs of back muscles: the rectus abdominis, internal oblique, external oblique, erector spinae, multifidus, gluteus maximus, and upper/lower fibers of the latissimus dorsi. The Mann-Whitney test was used to determine differences between the two groups. Results: Patients with LBP showed significantly increased amplitude and delayed onset time in the contralateral external oblique compared with healthy subjects. Conclusions: These results suggest that chronic nonspecific LBP patients have abnormal muscle activation in the external oblique during trunk rotation.

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Purpose: The purpose of this study was to examine the direction of the force at the ankle joint that reduces the anterior shearing force at the knee joint during muscle training of the vastus using a mathematical simulation. Methods: The functional effective muscle combined with the Hill model was used to estimate the muscle forces at the knee joint. The muscle lines of action were determined using the straight line model and the wrapping surface. Behavior of the shearing force at the knee joint was simulated by systematic manipulation of the direction of the force at the ankle joint. Result: When the direction of the force at the ankle joint changed, bordering on the line connecting the hip joint and the ankle joint, the anterior shearing force at the knee joint also changed. Conclusion: The findings of this study regarding the direction of the force at the ankle joint may provide the information needed to implement a safe muscle training method for anterior cruciate ligament injuries.

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Background and purpose: Circular sole of Ankle-Foot Orthoses (AFOs) with an immobile ankle joint has been shown to be effective for ensuring smooth walking regardless of walking speed, shoe height, and load carried. Energy efficiency was reported to be optimal when the circular sole radius was approximately 15% of subject's body height (BH) (Adamczyk, 2006). However, AFOs with such a radius are assumed to be unstable while standing and walking in daily life. Therefore, the purpose of this study was to clarify energetically optimal circular sole radius of AFOs with a fixed ankle joint in a range of radii. Method: Twelve male volunteers [mean age of 24.2 years (SD = 5.4 years)] participated in the study. They walked on a treadmill at a speed of 4.5 km/h for 7 min in each footwear condition. The footwear conditions were as follows: sneakers and AFOs with circular sole radius of 15%, 21%, 27%, 33%, 39%, or 45% BH. We measured the energy consumption rate during the last 1 min of the 7-min walk. Result: The energy consumption rate was minimum at a circular sole radius of 27% BH, and tended to increase with an increase in cadence. The energy consumption rate during walking with AFOs with a circular radius of 27% BH was not larger than that with sneakers. Conclusion: The energetically optimal circular sole radius of AFOs with an immobile ankle joint was 27% BH, which was larger than the value reported by Adamczyk (2006). Furthermore, the energy consumption with AFOs with a circular sole radius of 27% BH was similar to that with sneakers.

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Purpose: The purpose of this study was to clarify the factors affecting the perceived leg length discrepancy after total hip arthroplasty. Methods: The subjects were 67 patients who underwent primary unilateral total hip arthroplasty. We recorded age, gender, and body mass index as basic characteristics. We also measured radiographic leg length discrepancy, Crowe's classification, lateral pelvic tilt angle, and Japanese Orthopedic Association score preoperatively, and radiographic leg length discrepancy, lateral pelvic tilt angle, the amount of leg lengthening, length of offset, pain, hip extension angle, hip adduction angle, hip abduction angle, hip abductor strength, and perceived leg length discrepancy postoperatively. First, the correlation between the parameters and the perceived leg length discrepancy was verified using Spearman's correlation analysis. Subsequently, the parameters showing significant correlation with the perceived leg length discrepancy were used as independent variables in a hierarchical multiple regression analysis, with perceived leg length discrepancy as the dependent variable. Results: A hierarchical multiple regression analysis revealed that the operative hip adduction angle and postoperative lateral pelvic tilt angle were significantly related to the perceived leg length discrepancy and these relationships were independent of the actual postoperative radiographic leg length discrepancy (coefficient of determination, 0.619). Conclusion: The results suggest that an increase in the operative hip adduction angle and correction of lateral pelvic tilt are important for improving perceived leg length discrepancy.

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Purpose: The purpose of this study was to observe the effects of preoperative sarcopenia on the incidence of postoperative complications, physical function changes, and quality of life (QOL) from the perioperative to postdischarge stages in patients with gastrointestinal cancer. Methods: The study included 97 perioperative patients with gastrointestinal cancer [54 men and 43 women aged 62.5 ± 12.1 years (mean ± SD)] and with or without sarcopenia. Muscle mass was evaluated by the cross-sectional area of skeletal muscle on abdominal computed tomography images, muscle strength by isometric knee extension force, and physical performance by 6-minute walk distance, and patients were classified into three groups. The incidence of postoperative complications, physical function changes, and QOL were compared among the three groups from the preoperative to postdischarge stages. Results: The incidence of postoperative complications was significantly greater among patients with sarcopenia compared with the other groups, and QOL in these patients was significantly diminished. In addition, a trend toward decreased physical functioning after surgery was observed in patients with sarcopenia. Conclusions: Our findings indicate that perioperative sarcopenia influences the incidence of postoperative complications, physical function changes, and QOL after surgery in patients with gastrointestinal cancer.

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Purpose: This study examined the effects of exercise combined with branched chain amino acid (BCAA) supplementation on physical function in elderly Japanese in need of care. Materials and methods: This randomized controlled study enrolled 52 participants. Participants were randomly divided into the following two groups: a BCAA group (n=27) that ingested 6 g of BCAA supplement 10 min before starting exercise, and a control group (n=25) that ingested 6 g of maltodextrin. Exercises involved muscle strength exercises requiring 30% of voluntary maximum contraction, 10 min of aerobic exercise, and 15 min of balance function exercise. The 52 participants were followed for 3 months. We determined upper and lower limb isometric strength, grip strength, timed up-and-go test, functional reach distance (FRT), Frenchay Activities Index, and number of rehabilitation sessions. Evaluations were conducted before starting and after 3 months of supplementation. Results: The mean number of rehabilitation sessions was 18.8 for the BCAA group and 16.1 for the control group. The two factor analysis of variance showed that FRT was significantly differed in nutrition factor at the BCAA group after 3 months of supplementation. Other factors did not differed between two groups after 3 months. Conclusion: This study found that rehabilitation combined with BCAA supplementation improved FRT. This result suggests that one or two rehabilitation session each week combined with BCAA supplementation may improve balance function.

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[in Japanese]

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