We developed a device for treating stiff knees to increase the range of motion (ROM). To control below-knee active movement, a hybrid control system was employed. The system can switch two control modes according to torque angle characteristics that were observed by physical therapists (PTs) during the knee flexion ROM exercise. Angle control is adopted for the movement range and return range, while torque control is adopted for the pressure range. The knee flexion exercise using the device was performed in six patients, alternating between manual repetitive movement given by PT and automatic repetitive movement using the device every other day. The number of times of movement was repeated was eighteen for both sides. Load torque, ROM, and pain scale ratings were measured and compared between the first and 18th repetitions, and between manual and automatic operations at three stages: when the measurements were started, two weeks later, and at completion of measurement. ROM results showed a significant increase at the 18th repetition compared to the first repetition in all three stages for both manual and automatic bending movements. No differences were found between the two operations. The load torque value increased with time for both manual and automatic operations. With manual exercises, the torque showed a tendency to increase every time knee flexion movements were repeated. The pain scale ratings showed no significant difference between manual and automatic movements, but a score of the 18th repetition was significantly lower compared to the first repetition for automatic exercises at completion of measurements. These results suggest that the therapeutic device for treating stiff knees developed in this study provide the same effects to increase ROM at the same pain level as the manual ROM exercise given by PTs, and may play a significant role in general clinical use.

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The purpose of this study was to investigate the relationship between lower extremity strength and the ability to rise from a seated position in elderly patients.
The subjects were 205 elderly patients who were 65 years of age or older. They were classified into four groups according to their ability to stand up: those who were able to rise from a seat of 20 cm high, those able to rise from a seat of 30 cm high, and those able to rise from a seat of 40 cm high. Lower extremity strength was measured as isometric knee extension strength at the 90° angular flexion by a hand-held dynamometer. For analytic purposes, knee extension strength/body mass ratio was calculated. Age, height, body weight, Body Mass Index and isometric knee extension strength were analyzed. Logistic-regression analysis shows that knee extension strength is a critical factor affecting the ability to rise from a chair. Subjects with a knee extension strength of 35% or more were able to rise from a seat of 40 cm high. Subjects with a knee extension strength of 45 % or more were able to rise from a seat of 30 cm high, and subjects with a knee extension strength of 55% or more were able to rise from a seat of 20 cm high. On the other hand, subjects with a knee extension strength of under 20% were not able to rise from seat of 40 cm and 30 cm high, and subjects with a knee extension strength of under 30% were not able to rise from a seat of 20 cm high.
The results indicate that, for elderly patients, knee extension strength is an important factor for determining the ability to rise from a chair, and suggest that there is a certain threshold of knee extension strength under which no one can rise from a seated position.

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The aim of this study was to examine the relation between gait ability before operation and complication of deep vein thrombosis on lower limb after operation.
Subjects were 34 patients with rheumatoid arthritis who had undergone total knee arthroplasty. We separated patients into two groups based on D-dimer value on post-operative 7 day. If D-dimer on post-operative 7 day was more than 10 μg/ml, patients belonged to Group D, or if D-dimer was less than 10 μg/ml, they were Group N. We evaluated 8 factors; age, sex, operated side, Steinbrocker's stage and class, body weight, Functional Independence Measure, and the taken time of “The Timed Up & Go test”. All data were acquired before operation and compared these factors between two groups.
Among 8 factors, only the taken time of “The Timed Up & Go test” measured before operation was significantly different. Group D took significantly longer time to perform it than Group N. Other factors were not statistically different And the taken time of “The Timed Up & Go test” was dependent on progression of disease expressed by Steinbrocker's stage in the result of simple regression analysis.
This result suggests that patient with poor gait ability before operation has a high risk of complicated deep venous thrombosis after total knee arthroplasty. Thus, the improvement of gait ability not from after operation, but from before operation is important for patients with rheumatoid arthritis and it has a possibility to decrease the prevalence of complicated deep venous thrombosis after total knee arthroplasty.

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The objectives of this study were to investigate the relationship between the total duration of the swing phase and the time for reaching the minimum toe-floor clearance, which indicates the minimum distance between the big toe and the floor during the swing phase, in young and elderly adults, and to clarify the effect of aging on the minimum toe-floor clearance. Subjects were healthy women. The young group included 30 subjects of twenties, and the elderly group consisted of 10 subjects each of fifties, sixties and seventies. We measured basic data on walking, the minimum toe-floor clearance, and duration of the swing phase. The results demonstrated that the speed, step length and duration of the swing phase were significantly decreased in the elderly group in comparison with the young group. On the contrary, the minimum toe-floor clearance in all subjects was 17.3-18.2 mm, showing no difference between the two groups. Further, the duration of the swing phase and the time from toe off to the minimum toe-floor clearance were within the range of 0.37-0.39 sec and 0.13-0.15 sec, respectively, in both groups. These results indicated that aging did not have any effect on the minimum toe-floor clearance and that the minimum toe-floor clearance was kept in the elderly. It has been shown that the walking ability is decreased in elderly people due to aging, but in the present study aging showed no effect on the minimum toe-floor clearance. This suggests that the possible decrease in the minimum toe-floor clearance might be compensated by some mechanisms appropriate for individual functions in elderly people.

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The purpose of this study was to examine the useful evaluation for preventing falls in the residential elderly with dementia. Physical, intellectual and behavioral tests were carried out by Performance-Oriented Mobility Assessment, Mini-Mental State Examination and GBS scale, and Fall-Related Behavior Measurement, respectively. Only Fall-Related Behavior Measurement showed a significant difference between fall and non-fall groups in residential elderly with dementia. In logistic regression analysis, only Fall-Related Behavior Measurement showed a significant relationship with falls in the elderly. It was identified that fall risk would rise to twice whenever one dangerous behavior increases (Odds Ratio: 2.05, 95% Confidential Interval: 1.27-3.30, p < 0.00). These results suggested that it was important to evaluate not only physical and intellectual function but also dangerous behavior for falls prevention in the residential older with dementia.

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The purposes of this study were to examine the relationship between trunk motor function and changes in the center of pressure (COP) during fast lateral bending in sitting, and to investigate the relationship between these changes and the ability to walk in hemiplegic patients. Subjects were thirty-three hemiplegic patients (right hemiplegia, 17; left hemiplegia, 16; age, 63 ± 12 years). The directions of the motion were measured on both the paralyzed and healthy sides of the body.
The COP displacement in right-left direction was detected by means of force plates at a sampling rate of 500 Hz. COP trajectories moved in the opposite direction of the motion immediately after a starting signal. Thereafter these trajectories rapidly moved in the direction of the motion. The maximum amplitude of the initial COP shift and the maximum velocity of the COP were defined as A₁ and V_max, respectively. The distance that the COP moved from the neutral position to the maximum shift position was defined as D_cog. Trunk motor function in hemiplegia was evaluated using the neck, trunk and pelvic motor function test (NTP), which was classified into six stages. In addition, the degree of hemiplegia with which walking remains possible was determined using the 10-meter walking speed.
The correlation between A₁ in both directions and NTP stage was significant (p < 0.01). The subjects above NTP stage 4 tended to have a larger A₁ value than the other hemiplegic patients. The relationship between V_max in both directions and NTP stage was also significant (p < 0.01). The correlation between D_cog in the healthy side and NTP stage was significant (p < 0.05), while the correlation between D_cog in the paralyzed side and NTP stage was not. The relationship between walking speed and A₁ in the healthy side was significant (p < 0.05). while that in the paralyzed side was not. The correlation between walking speed and D_cog was significant (p < 0.01).
It was thought that the hemiplegic patients with good trunk motor function were able to produce the moment of gravity for fast movement. Moreover, lower limb stability may induce a larger center of gravity shift. The relation between walking speed and A₁ is thought to be influenced by the condition of the lower limb in addition to pelvis elevation. The results indicated that analysis of changes in COP during fast lateral bending in sitting is useful for evaluation of trunk motor function.

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The purpose of this study was to determine the effects of toe-clips, pedaling rate and work-load on the muscle activity of the lower extremities during ergometric cycling. Ten healthy subjects (mean age 24.0 ± 2.6 years) participated in this study. Electromyographic activity during ergometric cycling was measured in the rectus femoris, vastus medialis, vastus lateralis, semimenbranosus, biceps femoris, gastrocnemius medialis, and tibialis anterior. Ergometric cycling was performed under two toe-clip conditions (with or without), two pedaling rates (40 rpm, 60 rpm), and three work-loads (0.5 kp, 1.0 kp, 2.0 kp). The muscle activity of the rectus femoris was significantly greater with use of the toe-clips than without. However, muscle activity of the semimenbranosus and biceps femoris was greater without the use of the toe-clips during the knee extension phase (down-stroke).
By varying the pedaling rate, there was a significant difference in the muscle activity of all the muscles except for the rectus femoris, semimenbranosus and biceps femoris during the knee flexion phase (up-stroke). By increasing the work-load, the activity of all the muscles also increased, except for the semimenbranosus and biceps femoris.
These results suggest that toe-clips, pedaling rate and work-load have different effects on muscle activity in the lower extremities during ergometeric cycling.

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