The present study examined whether a sit-to-stand score can be related to the force-generating capacity of knee extensor muscles. Fifty-seven subjects (28 men, 63.0+/-7.8 yrs, and 29 women, 64.2+/-7.5 yrs, means+/-SDs) performed a 10-repeated sit-to-stand test as fast as possible, on a steel molded chair. The time taken (T(sit-stand)) was measured with a manual stopwatch. The leg length (L), defined as the distance from the great trochanter of the femur to the malleolus lateralis, was measured using a tape. A power index of the test (P(sit-stand)) was calculated by using the following equation: P(sit-stand)=(L-0.4) x body mass x g x 10/T(sit-stand). The cross-sectional area of the quadriceps femoris muscle (CSA(KE)) and the maximal voluntary isometric knee extension force (F(KE)) were measured using MRI and a static myometer, respectively. There was no significant correlation between T(sit-stand) and each of CSA(KE) and F(KE). On the other hand, the P(sit-stand) was highly correlated with CSA(KE) and F(KE), even after the influence of body mass and L was statistically eliminated. These results indicate that P(sit-stand), derived from three variables of body mass, leg length, and time taken for a sit-to-stand test, can be a useful index to assess the force-generating capacity of the knee extensor muscles of elderly individuals.

https://www.jstage.jst.go.jp/article/jpa2/28/3/28_3_123/_pdf

Sit-to-stand test to evaluate knee extensor muscle size and strength in the elderly: a novel approach.

Summary
A prospective 1-year study showed that fall incidence was 50% in women with rheumatoid arthritis. Multivariate analysis identified swollen joint count, use of antihypertensives or diuretics, one-leg standing time, and sway area measured by stabilometer as significant parameters associated with falls.

/pdf/incidence-and-risk-factors-of-falling-in-ambulatory-patients-185gdu1yvw.pdf

Incidence and risk factors of falling in ambulatory patients with rheumatoid arthritis: a prospective 1-year study

Kinematics of stair descent in young and older adults and the impact of exercise training.

https://repository.kulib.kyoto-u.ac.jp/dspace/bitstream/2433/143669/1/j.archger.2010.08.003.pdf

Age-related muscle atrophy in the lower extremities and daily physical activity in elderly women.

Locomotor function declines in old age. Based on 55 studies, this review appraises current evidence on the impact of physical training interventions on locomotor function in older people. Overall, the literature indicates that physical training can have a beneficial impact on locomotor function in older people. This also holds true in various sub-populations including those who are very old, those who have functional limitations and those with chronic health problems. Improvements in locomotor function can be seen within 4-6 weeks of physical training, although the potential that improvements may appear earlier has not been investigated. Recent studies provide evidence of a dose-response relationship between intensity of strength training and improvement in locomotor function in older people. However, whether such a relationship exists for other training modes has not yet been investigated. Based on current evidence, the optimal training modes or combination of training modes (strength, aerobic, balance, coordination, etc.) and the optimal frequency of training for improvement in locomotor function are unclear.

The Impact of Physical Training on Locomotor Function in Older People

The purpose of this study was to investigate the hypothesis that the reduction in walking ability is due to muscle atrophy in the lower limb muscles with aging using equational structure modeling as well as investigate the influence of muscle on walking ability. The subjects consisted of 127 per. sons (57 males and 70 females) aged 2084 year, who were grouped into 6 age brackets of 20-39, 40--49, 5059, 60-V69, 70.74, and 75 or older. Using MRI, muscle cross-sectional area was measured on psoas major and thigh muscle (divided into extensor and flexor). For walking patterns , each subject walked along a 7-m walking passage at normal speed for VTR-recording of the motion. The resulting pictures were used to analyze stride length, trunk inclination and walking speeds. Walking speeds showed a statistically significant decrease in value from the 50's age group in males and the 60's age group in females when compared with the 20•`39 age bracket (p<0.05). In males, a significant co-relationship was observed only between the muscle cross-sectional area of thigh extensor and walking speed (p<0.01) while in females, a significant co-relationship was found between the muscle cross-sectional area of psoas major (p<0.001) /thigh muscle extensor (p<0.01) and walking speed. These results indicate that the muscle atrophy with aging in psoas major and thigh muscle extensor is a factor responsible for the decrease in walking speed. Meanwhile, a differ. ence in sex was observed between the muscle cross-sectional area of psoas major and walking speed. It was considered that the muscle atrophy rate of the female's psoas major being higher than the male's influenced this. Furthermore, it was suggested possibility that the decline of walking ability is due to decreased muscle mass of the lower limbs with aging. (Jpn. J. Phys. Fitness Sports Med. 2000, 49 : 589•`596) key word : aging, muscle cross-sectional area, psoas major, walking speed

https://www.jstage.jst.go.jp/article/jspfsm1949/49/5/49_5_589/_pdf

Relationship between reduction of hip joint and thigh muscle and walking ability in elderly people

The relationship between muscle cross-sectional area (CSA) of the hip joint and lower extremities and speed of stair ascent/descent was investigated in a sample of 127 elderly women (ages: 60–70 years old). The participants performed ascent and descent of stairs with 12 steps for which the speeds for ascent and descent separately from video film were calculated. The ascent speed significantly correlated with CSAs of knee extensor (r = .21, p<.05) and psoas major muscle (r = .25, p<.01), which were assessed by magnetic resonance imaging. The descent speed also correlated with CSAs of the same muscle groups (with knee extensor: r = .20, p<.05, with m. psoas major: r = .18, p<.05). The rest of the muscle groups were not related to the ascent/descent speeds of the step. These results suggested that the muscle mass of the knee extensor muscle group and also the psoas major muscle could be a factor in potential capacity in stair ascent/descent by humans.

Determinants for Stair Climbing by Elderly from Muscle Morphology

In order to clarify the effect of exercise on the walking performance and the muscle volume in lower limbs, elderly athletes long continuing to be trained and untrained elderly were compared with regard to their muscle cross-sectional area (CSA) of m. psoas major, thigh muscle and crus muscle and their walking ability. The subjects used consisted of thirty-six 80's-aged male and 70's-aged female elderly athletes and twenty-four elders having no regular exercise (control male group : CM, control female group : CF). The elderly athletes were further divided into two groups in accordance with their results of Japan Fitness Test (high performance male group : HPM, low performance male group : LPM, high performance female group : HPF, low performance female group : LPF). The walking performance was evaluated by analyzing their walking speed, stride-length and step rate during walking along a 15 m-strip of passage at normal and fast paces using videotaping. The muscle CSA was determined at m. psoas major, thigh muscle (extensors and flexors) and crus muscle (m. tibialis anterior and m. triceps surae) using MRI. As for the walking speed and stride-length at the normal pace, only HPM and HPF showed significantly higher values than CM and CF (male : p<0.05, female : p<0.01). Meanwhile at the faster pace, HPF and LPF showed significantly higher values than CF in female (HPF : p<0.01, LPF : p<0.05) and in the case of males, only HPM have a higher value only of the walking speed than CM (p<0.05). The CSA of m. psoas major in HPM and HPF significantly higher than that in CM and CF (all p<0.05), while in CSAs of knee extensor muscles and m. triceps surae, the statistical differences were not consistent among male and female groups. The results suggested that greater muscle mass of m. psoas major could influence higher walking speed in elderly people, and might be affected by regular exercise training. (Jpn. J. Phys. Fitness Sports Med. 2001,50:149•`158) key word : elderly athlete, psoas major, walking ability

Effect of long-term exercise on walking ability in elderly people

The ability to walk is just as important for the elderly as it is for young people. In fact, in the elderly, decreased mobility limits function in daily life and can lead to more serious situations (e.g., becoming bedridden). The elderly population has increased over the last decade, and many researchers have studied the mobility of the elderly. However, the focus of most studies has been to facilitate recovery of bedridden individuals and prevent the elderly from becoming bedridden, and particularly to prevent fall-induced fractures, which often cause the elderly to become bedridden. However, about 70-80% of the elderly population do not require care, and it is necessary to conduct research on the maintenance of activities of daily living to make it possible for the elderly to work or volunteer. From this perspective, mobility is an important physical factor. Mobility is dependent on muscle activity and it has long been known that aging reduces muscle mass. Therefore, it is feasible to assume that reduced muscle mass leads to decreased ability to walk, and we have proven that there is a close correlation between the two. When presenting the idea of strength training to the elderly, it is appropriate to focus on the maintenance and improvement of mobility, not on the training itself. The results of our research can be summarized as follows: Muscle mass decreases with age, with the legs being affected to a greater degree than the arms. Moreover, muscle atrophy is dependent on weakening of muscle fibers, especially fast-twitch (Type II) fibers. Reduced lower limb muscle mass increases the risk of falling and can decrease walking ability to a degree that can affect daily living activities. In order to improve reduced muscle mass in aging, it is important to use an exercise program that is designed to strengthen fast-twitch fibers, which can be followed even by the elderly. Since walking therapy mostly mobilizes slow twitch fibers, it is not effective in preventing and improving muscle atrophy. It is important to have an exercise program that is designed to mobilize fast-twitch fibers. (Jpn. J. Phys. Fitness Sports Med. 2003, 52 Suppl : 17•`30) key word : aging, muscle mass, fast-twitch fiber, atrophy, strength training

Jundong Kim

Papers

Relationship between reduction of hip joint and thigh muscle and walking ability in elderly people

Determinants for Stair Climbing by Elderly from Muscle Morphology

Effect of long-term exercise on walking ability in elderly people

Effect of strength training on aging muscles of elderly people

Elucidating the potential pharmaceutical mechanism of Gyejibokryeong-hwan on rosacea using network analysis