Previous studies have evaluated reliability and validity of clinical measurements of femoral and tibiofibular torsion, however, the results are conflicting, warranting an alternative method. The authors developed modified methods of measuring femoral and tibiofibular torsion using different reference axes, and validity and reliability of the modified and existing methods were examined in healthy subjects. Reference values were established using magnetic resonance imaging (MRI) for the validity study. There were significant differences between all clinical methods and corresponding MRI outcomes (P <0.05), whereas Pearson's correlation coefficients between the clinical methods and MRI ranged from 0.67-0.92. For modified methods, intraclass correlation coefficients were 0.89-0.97, whereas those of existing methods were 0.75-0.81. Modified methods were more precise, with standard error of measurements (SEM) of 1.5-2.9 degrees , compared to existing methods (SEM=4.0-5.1 degrees). These results indicate that clinical methods available currently do not accurately measure true torsion of the femur and tibia. Nevertheless, the clinical methods may be useful for screening and descriptive purposes as indices of true torsion, and use of different reference axes could improve their reliability.

The current study was conducted to examine ethnic, gender, and age-related differences in femorotibial angle (FTA), femoral antetorsion and tibiofibular torsion. Healthy Japanese (n = 120) and Australian Caucasian (n = 82) subjects were examined using a series of clinically reliable methods for measuring FTA and torsion of the lower limb. Subjects between 18-29 years of age were categorized as younger, 30-59 years as middle age, and 60 or more as older age. Three-way analysis of variance was utilized for data analysis. The Japanese subjects had significantly greater FTA (more varus) than the Australian subjects (P < 0.001). Femoral antetorsion in the Japanese subjects was significantly smaller in middle and older age groups than younger group (P < 0.05), but did not differ between the age groups in the Australian subjects. Further, tibiofibular torsion in female subjects was significantly greater in younger and middle age groups than the older age group (P < 0.01), but was not different between different age groups in males. The results suggest that healthy Japanese may have more genu varus alignment compared to the corresponding Australian population. Age-related ethnic and gender differences in femoral and tibiofibular torsion are worthy of further study.

This study investigated predictors of outcome for a three-month group-exercise program among a communitydwelling Japanese population aged over 65 (nϭ42). The primary outcome variable was health-related quality of life (HRQOL) using the Short Form 36 (SF-36). Candidate predictors included demographic variables, medical history of chronic diseases, and lifestyle-related factors, including selfreported home exercise at baseline examination. At follow-up, only the vitality domain of the SF-36 was significantly improved. Self-reported home exercise and younger age at baseline were significant predictors of a good outcome in the mental and physical components, respectively, of the SF-36. These results indicate that group exercise may be effective to improve the vitality component of HRQOL for Japanese seniors. However, the effects on the physical components of HRQOL are limited. Home exercise and younger age may influence the effects of group exercise on HRQOL for this population.

Background In patients with knee osteoarthritis (KOA) undergoing knee arthroplasty (KA), lower-limb motor function tests are commonly measured during peri-surgical rehabilitation. To clarify their sources of variation and determine reference intervals (RIs), a multicenter study was performed in Japan. Methods We enrolled 545 KOA patients (127 men; 418 women; mean age 74.2 years) who underwent KA and followed a normal recovery course. The surgical modes included total KA (TKA), minimally invasive TKA (MIS-TKA), and unicompartmental KA (UKA). Motor functions measured twice before and two weeks after surgery included timed up-and-go (TUG), maximum walking speed (MWS), extensor and flexor muscle strength (MS), and knee range of motion (ROM). Multiple regression analysis was performed to evaluate their sources of variation including sex, age, BMI, and surgical mode. Magnitude of between-subgroup differences was expressed as SD ratio (SDR) based on 3-level nested ANOVA. SDR≥0.4 was set as the threshold for requiring RIs specific for each subgroup. Results Before surgery, age-related changes exceeding the threshold were observed for TUG and MWS. Between-sex difference was noted for extensor and flexor MS, but extension and flexion ROMs were not influenced by sex or age. After surgery, in addition to similar influences of sex and age on test results, surgical modes of UKA and MIS-TKA generally had a favorable influence on MWS, extensor MS, and flexion ROM. All motor function test results showed a variable degree of skewness in distribution, and thus RIs were basically derived by the parametric method after Gaussian transformation of test results. Conclusions This is the first study to determine RIs for knee motor functions specific to KOA patients after careful consideration of their sources of variation and distribution shapes. These RIs facilitate objective implementation of peri-surgical rehabilitation and allow detection of patients who deviate from the normal course of recovery.

A cross-sectional study was designed for this investigation using a healthy Japanese population. The objectives of this study were to confirm gender and age-related differences in axial alignment of the lower limb, and to investigate the correlation between femorotibial angle and axial alignment of the lower limb among a healthy Japanese population. Although axial alignment of the lower limb has been defined as one of the associating factors for osteoarthritis of the knee along with varus and valgus deformity, the results in the literature are inconsistent. Since there is gender difference in femorotibial angle, axial alignment of the lower limb should show the difference if it is an associating factor for osteoarthritis of the knee. Few studies have been conducted to investigate gender difference in axial alignment of the lower limb. One hundred and forty four healthy Japanese subjects took part in the study. Reliable clinical methods of measuring femoral torsion, tibiofibular torsion, rotational range of motion of the hip and knee joints, and femorotibial angle were employed utilizing a digital inclinometer. Two way ANOVA and Pearson product-moment correlation analysis were used for statistical analyses. Axial alignment of the lower limb was different between genders (p<0.05). An age-related difference was also shown in hip rotation (p<0.05). Further, the femorotibial angle was significantly correlated with hip and knee joint rotation (p<0.05) in older males and younger females. This study implied that axial alignment of the lower limb may be related to deformity of the knee joint.