The purpose of this study was to investigate the effect of leg strength on the walking ability of elderly women. Forty-four elderly women staying at home were selected as the subjects (average age: 80.1 ± 3.9). Their walking ability was followed for two and a half years. “Normal” and “maximum” walking speeds were tested before and after two and a half years on a 10-meter straight course. After two and half years, we divided the subjects into two groups, based on their initially measured leg strength scores. No subjects in the high leg strength group required a cane to walk; however, nine subjects in the low leg strength group used a cane (p < 0.01). The normal and maximum walking speeds of 40 subjects who were able to participate in the walking re-test, two and a half years later, decreased on average by 11% and 16%, respectively (p < 0.01). The rate of change in walking speeds decreased with ages (normal: y = -1.219x + 86.53, r = - 0.376, p < 0.05, maximum: y = - 1.477x + 102.30, r = -0.431, p < 0.01), and mostly depended on the leg strength score (normal: y = 0.002x² + 1.183x -158.4, r = 0.789, p < 0.01, maximum: y = -0.002x² + 1.172x -164.0, r = 0.801, p < 0.01). The correlation between the leg strength score and the rate of change in walking speed was that the subjects with less muscle strength showed a more rapid decline in walking speed, in spite of the fact that there was no change in the walking speed of the group with the initially high leg strength. Thus, this study suggested that elderly women with high leg strength showed no change in walking speed for two and a half years, while the subjects in the lower leg strength group showed a remarkable drop in their walking capability and walking speed.

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Enthesopathy, which occurs frequently among young athletes, may be caused by excessive tightness and/or alignment of the lower extremities. The purpose of this study was to examine factors related to the occurrence of enthesopathy in junior high school soccer players in order to search for the possibility of intervention to prevent sport injury during the growth period.
The subjects were 81 male soccer players who played in the extramural soccer teams of three junior high schools. They were divided into two groups: 13 subjects who had experienced enthesopathy problems, and a group of 68 who had not. Investigation and measurement were performed regarding height growth velocity, measurements of muscle tightness and alignment, etc.
The results revealed that there was no connection between the phase of height velocity curve and enthesopahy. The results of the discriminant analysis based upon 17 measured values were not significantly different between the 2 groups. When the 17 values were reduced to 7 values in consideration of the F value of each value, the results of the discriminant analysis were significantly different between the 2 groups (p < 0.05). The body fat ratio, team of participation, tightness (right ilio-psoas, hip adductors, right hamstrings, and left quadriceps), and alignment (left leg-heel angle) were found especially helpful in discriminating the occurrence of enthesopathy among the junior high school soccer players. This suggests that there is a possibility of intervention to prevent sports injury during the growth period.

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Dysfunction of hip abductors, important players for the medial-1ateral stability of the pelvis, is characterized by positive Trendelenburg's sign, which is often seen in patients with hip disorders. We conducted this pilot study to determine whether pelvic tilt angle affects hip abductor strength in normal young female subjects.
Eleven subjects (20.0 ± 1.2 years) volunteered to participate. Isometric hip abductor torque was measured by means of a hand-held dynamometer in a supine position. Pelvic tilt angle was changed at 5 and 10 degrees with a hard pillow placed posterior to the lumbar spine for anterior tilt and posterior to the sacrum for posterior tilt of the pelvis.
Abductor torque was found to be the greatest in a neutral pelvic tilt angle. An angle-dependent decrease in abductor torque was observed in both anterior and posterior tilt.
Changes in pelvic tilt angle, whatever anterior or posterior, decreased hip abductor strength in normal young female subjects. Further studies are needed to determine whether anterior tilt due to flexion contracture of the hip and posterior tilt due to kyphotic deformity of the lumbar spine are involved in dysfunction of the hip abductors in patients with hip disorders.

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The purpose of this study was to examine the effects of heat and cold exposure on inflammation, joint destruction, and skeletal muscle in rats with adjuvant arthritis. Thirty-one Lewis rats (7 week-old, female) were divided randomly Into 6 groups: control (n=5), heat-exposed (H, n=5), cold-exposed (C, n=5), adjuvant arthritis (AA, n=6). AA plus heat-exposed (AAH, n=5) and AA plus cold-exposed (AAC, n=5). AA was induced via intradermal injection of complete Freund's adjuvant (3.0 ml) into the center of the back region. One week after the injection, bilateral hindlimbs of the H and AAH groups were immersed in hot water (42℃) for 60 min/day, 5 days/week for 2 weeks. Similarly, bilateral hindlimbs of the C and AAC groups were Immersed in cold water (10℃). Upon comparison to the AA group, which were obtained through disuse of skeletal muscle, the AAH group displayed an increase in diameter of types I and 11 muscle fiber in the form of elevated heat shock protein 70; however, an accelerated ankle joint destruction was observed. On the other hand, the AAC group exhibited decreased inflammation and an increase in diameter of type I muscle fiber characterized by increased capillary number In soleus when compared to the AA group. These results demonstrate that heat and cold exposure afford a preventive effect with respect to muscle atrophy by disuse in AA rats; furthermore, cold exposure may be applied more safely than heat exposure.

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The purpose of this study was to characterize rotation velocities of the pelvis, femur and leg in individuals with knee osteoarthritis (OA) and find the differences between these of asymptomatic persons during walking.
Five healthy young persons, 8 healthy elderly persons and 21 knee OA subjects (Grade II, 9; Grade III, 7; Grade IV, 5) were studied.
The magnitude and temporal characteristics of rotation velocity were significantly different between normal persons and knee OA subjects. Rotation of the pelvis was not different between the two groups. The knee OA decreased internal rotation velocity during loading response and external rotation during the midstance phase. Normal knees showed rotation movement of the leg during the early stance phase, however knees OA showed a decrease in rotation movement of the leg.
This study demonstrated differences in leg rotation velocity power spectra for participants with knee OA when compared with normal knees. In knee OA subjects, first peak frequency was shifted to a low frequency, and showed an inequitable spread. It means loss of rotation movement harmony. These findings indicate abnormal knee movement in knee OA.
The rotation velocity measurements used in this study may be useful in clinical practice.

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The relationship between the Inverse fluctuation of the center of pressure (COP) at gait initiation and toe muscle power, dorsiflexion power of ankle, static balance was studied among the elderly.
The COP of the foot pattern during gait initiation has been well described as initially moving backward towards swing foot. Although this basic process is uniform regardless of age, the Inverse fluctuation of the COP tends to be small in the elderly.
The purposes of this study were to clarify the COP during gait initiation among the elderly and related factors determining the COP. The first part of this study measured the following parameters of 15 eldely subjects. The parameters were 1) inverse fluctuation of sagital direction of the COP (As), 2) inverse fluctuation of lateral direction of the COP (Al), 3) the quiet-standing balance (Bd, Ad), 4) premotor time of the inverse fluctuation of the COP (Cd), 5) toe muscle power (Fg), 6) grip force slope (Gs), 7) pre-motor duration of the grip (Gd), 8) motor duration of the grip (Tp), and 9) dorsiflexion power of ankle (Dt). In the second part, the results were compared with those of five young subjects.
The results were as follows. Elderly subjects indicated a significantly positive correlation between As and Al, Cd and Gd, and a negative correlation between Al and Bd. Gs was significantly smaller in elder subjects than in young subject. Al and Gs were greater in exercises than in preexercises, and Bd and Gd were smaller in exercises. This study could not prove that the inverse fluctuation of the COP relates to some factors. but the results suggested the possibility to clarify the COP shift mechanism.

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A study was performed to investigate the pelvic sway from the dynamic EMG frequency characteristic (MPFR), muscle tissue morphology, and the maximum isometric hip abductor torque. The subjects were 13 patients with hip disease who underwent surgery at Kyushu University Medical Hospital and 10 healthy persons. Before surgery, the maximum isometric hip abductor torque was measured. The electrodes were placed on the belly of the gluteus medius muscle on the operative side (or on the right side in healthy persons), and reflective markers were placed on the anterior superior iliac spine on both sides of the pelvis. Then, dynamic EMG frequency analysis (wavelet time-frequency analysis) and three-dimensional motion analysis (pelvic tilt angle in the frontal plane, pelvic rotation angle, and lateral displacement of the pelvis in the horizontal plane) were conducted concurrently during a 10-m free walk. A biopsy specimen was taken from the belly of the gluteus medius muscle at the time of surgery, and the muscle fiber type was classified by ATPase staining. Furthermore, the muscle fiber diameter of type I and type II fibers were measured by using image processing software (NIH image). It was found that there was a significant positive correlation between the MPFR and the diameter of type II fibers or the walking ability score (JOA hip score) in the patients. The pelvic tilt angle and pelvic rotation angle were deviated significantly from the normal base as compared with the healthy persons. Moreover, multiple regression analysis showed that the maximum isometric hip abductor torque and MPFR were important regulatory factors of the pelvic tilt angle in the frontal plane.

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