Sohee Shin

Setting the criterion for fall risk screening for healthy community-dwelling elderly

This study aimed to develop a criterion for screening high risk elderly using Demuras fall risk assessment chart (DFRA), compared with the Tokyo Metropolitan Institute of gerontology (TMIG) fall risk assessment chart. Participants included 1122 healthy elderly individuals aged 60 years and over (380 males and 742 females) 15.8% of whom had experienced a fall. We assessed fall risk of the elderly by DFRA and TMIG. To develop a criterion for screening high fall risk subjects among community-dwelling elderly, receiver-operating-characteristic (ROC) analysis was conducted using fall experience (separated into the categories of faller and non-faller) and the following fall risk scale scores: (1) TMIG score, (2) DFRA score, and (3) potential for falling score according to the DFRA (summing the scores of three items). In ROC analyses, the area under the ROC curve (AUC) for evaluating the potential for falling gave a value of 0.797 (95% CI=0.759-0.834) which proved better than the evaluation of the overall TMIG (0.654, 95% CI=0.600-0.706) and DFRA scores (0.680, 95% CI=0.633-0.727). Assessment of the potential for falling and fall experience are of benefit in screening for elderly persons deemed to be at a high fall risk. Further examinations based on the prospective data setting will be required.

Age and sex differences in various stepping movements of the elderly

Aim:  This study aimed to examine sex and age differences of various stepping movements in the elderly and to clarify useful stepping movements for evaluation of their dynamic balance.

The relationship of age and leg strength in the step test with stipulated tempo in the elderly

This study aimed to examine age differences in the step test with stipulated tempo, a test of dynamic balance ability in the elderly. One hundred eighty-nine healthy elderly people (96 men and 93 women) executed the step test for 20 s twice, with adjustments of the metronome (40 bpm, 60 bpm and 120 bpm). The knee extension strength of both legs was each measured twice. Evaluation parameters included the time difference between metronome sound and the time when each foot hit the ground, two-leg support time, and one-leg support time. The time difference and two-leg support time were significantly longer in the order of 40 bpm, 60 bpm, and 120 bpm tempos, and one-leg support time was shorter in the 40 bpm tempo than the 60 bpm and 120 bpm tempos. A significant age difference was found in the 40 bpm or 60 bpm tempo, and the former two parameters were longer in the older groups and the one-leg support time was shorter. Three evaluation parameters showed significant relationships with knee extension strength. In conclusion, because the step test with a slow tempo (40 bpm or 60 bpm) requires longer one-leg support time, it is effective for the evaluation of dynamic balance ability and leg strength of the elderly.

Effectiveness of the 1rm Estimation Method Based on Isometric Squat Using A Back-dynamometer

Demura, S, Miyaguchi, K, Shin, S, and Uchida, Y. Effectiveness of the 1RM estimation method based on isometric squat using a back-dynamometer. J Strength Cond Res 24(10): 2742-2748, 2010-This study aimed to clarify the relationships between isometric squat (IS) using a back dynamometer and 1 repetition maximum (1RM) squat for maximum force and muscle activities and to examine the effectiveness of a 1RM estimation method based on IS. The subjects were 15 young men with weight training experience (mean age 20.7 ± 0.8 years, mean height 171.3 ± 4.4 cm, mean weight 64.4 ± 8.4 kg). They performed the IS with various stance widths and squat depths. The measured data of exerted maximum force and the action potential of the agonist muscles were compared with the 1RM squat data. The exerted maximum force during IS was significantly larger in wide stance (140% shoulder width) than in narrow stance (5-cm width). The maximum force was significantly larger with decreased knee flexion. As for muscle activity, the % root mean square value of muscle electric potential of the rectus femoris and the vastus lateralis tended to be higher in wide stance. As for exerted maximum force, wide stance and parallel depth in IS showed a significant and high correlation (r = 0.73) with 1RM squat. Simple linear regression analysis revealed a significant estimated regression equation [Y = 0.992X + 30.3 (Y:1RM, X:IS)]. However, the standard error of an estimate value obtained by the regression equation was very large (11.19 kg). In conclusion, IS with wide stance and parallel depth may be useful for the estimation of 1RM squat. However, estimating a 1RM by IS using a back dynamometer may be difficult.

Comparison and age-level differences among various step tests for evaluating balance ability in the elderly

This study aimed to examine the difficulty among various step tests (place step, forward single step, forward double step, forward right single step and stairs step) in evaluating the dynamic balance in the elderly and their age level differences. Thirty-two healthy elderly people (age 71.4+/-6.4 years) and twenty young people performed step tests for 10 s to the pace of a metronome (120 bpm). Evaluation parameters were the time difference between the metronome sound and the time when each foot hit the ground as well as the stride time. The forward single step test had significantly larger values for both of the above parameters than the other tests. A significant age level difference was found in the forward single step test for the time difference and in the forward single step and stairs step tests for the stride time, being longer in the elderly. It was concluded that the forward single step test has larger age-level differences and is more difficult to carry out than the other step tests.

Effect of hypoxic training on inflammatory and metabolic risk factors: a crossover study in healthy subjects

The purpose of this study was to investigate the influence of hypoxic physical exercise on metabolic syndrome (MS) risk markers and high‐sensitivity C‐reactive protein (CRP) and to compare its effects on preperitoneal fat, arterial stiffness, and several blood parameters related to MS to those of a control group who trained under normoxic conditions. Fourteen healthy men were examined. Participants performed treadmill exercise 3 days per week for 4 weeks, under either normobaric hypoxic or normobaric normoxic conditions, for 50 min (including a 5‐min warm‐up and 5‐min cool down) after a 30‐min rest period. Exercise was performed at a heart rate (HR) corresponding to 60% of the HR at each individuals maximum oxygen uptake. Training under the different environmental conditions was performed 4 months apart to ensure a sufficient washout period. Waist circumference, preperitoneal fat thickness, brachial‐ankle pulse wave velocity, and high‐sensitivity CRP after training were significantly lower in the hypoxic group than in the normoxic group. Our results suggest that regular short‐term hypoxic training may more effectively reduce arterial stiffness, and thus prevent arteriosclerosis, compared to training performed at a similar exercise intensity under normoxic conditions.

Relationship between the obstacle height cognition and step movement in the elderly

BackgroundThis study examines the effect of obstacle height cognition (OHC) on single-leg forward step (SFS) and Obstacle-SFS.MethodsIn the SFS test, participants stepped 25 cm forward with one leg and returned it to its original position five times as quickly as possible. The Obstacle-SFS added an obstacle to the above condition in the SFS test. The participants were divided into two groups: tripping group, which tripped over an obstacle in the Obstacle-SFS test; and non-tripping group, which did not trip. Parameters were step time (T), the time it took to step forward (F), and the time it took to return to the original position (R). The OHC was determined by the difference between the elevated leg’s height and the obstacle height (10 cm), which was set at 60 cm in front of the participant.ResultsOHC showed a significant and moderate relationship with all parameters of Obstacle-SFS (OSFS-T, OSFS-F and OSFS-R). The tripping group had significantly larger values in the OHC, OSFS-T and OSFS-F than the non-tripping group.ConclusionsIn conclusion, the differences in obstacle height cognition ability may affect Obstacle-SFS movement.

Sex and age-level differences of walking time in preschool children on an obstacle frame

BackgroundStepping over an obstacle is a kind of compound movement that makes walking more difficult, especially for preschool children. This study examines sex and age-level differences in walking time in preschool children on an obstacle frame.MethodsThe participants included 324 healthy preschool children: four-year-old boys (51) and girls (51), five-year-old boys (50) and girls (60), and six-year-old boys (62) and girls (50). A 5 cm- or 10 cm-high obstacle (depth 11.5 cm, width 23.5 cm) was set at the halfway point of a 200 cm × 10 cm walking course.ResultsThe participants walked to the end of the course and back as fast as possible under three conditions: no obstacle, low obstacle and high obstacle. Walking time showed age-level differences in all conditions, but there were no differences in sex. Age levels were divided into two groups, with one group within the first six months of their birthday, and the second group within the last six months of that year. Walking time for children in the first half of their fourth year was longer than that of the five- and six-year-old children. In addition, for children in the last half of their fourth year, walking time was longer than both sexes in the last half of their fifth and sixth years. The children in the latter half of their fifth year had a longer walking time in the high obstacle condition than those in the last half of their sixth year. In the four-year-old participants, walking time was shorter with no obstacles than with a high obstacle frame.ConclusionsIn the above data, obstacle course walking time does not show a gender difference, except that the four-year-old participants needed longer than the five- and six-year-old children. Setting the obstacle 10 cm high also produced a different walking time in the five- and six-year-old participants. The high obstacle step test (10 cm) best evaluated the dynamic balance of preschool children.

Effects of Prior Use of Chopsticks on Two Different Types of Dexterity Tests: Moving Beans Test and Purdue Pegboard

The Purdue Pegboard and Moving Beans with Tweezers test have been used in the rehabilitation of persons with nervous system disorders; however, these two tests differ in their methodology. In the latter test, the testee picks up items with chopsticks or tweezers, but in the former test, the testee grasps items directly with the fingers of one hand. Use experience of a tool may strongly influence performance. The present study examined the use of chopsticks in daily life on performance of the two tests of finger dexterity by two groups of 20 youths who habitually used chopsticks to eat and 20 who did not. Three 30-sec. trials with the dominant and nondominant hands were given. Analysis of variance gave a main effect for number of beans moved between the two groups, hand (nondominant vs dominant), and trials. Significantly more beans were moved by the group with prior chopsticks use than the nonusers by the dominant hand than the nondominant hand, and on Trials 2 and 3 than Trial 1. For the Purdue Pegboard, the only significant difference for trials showed fewer pegs moved on Trial 1 than Trial 3. In conclusion, the groups who habitually used chopsticks performed better on the Moving Beans with Tweezers test than the group without such experience. Also, the marked laterality and practice effects for chopstick users was not observed on the Purdue Pegboard.

Reliabilities and inter-relationships of various stepping tests and evaluation parameters for the elderly

The reliability, inter-relationship, and utility of stepping tests for dynamic balance evaluation in the elderly were examined. Seventy-seven women of mean age 75.4 years performed in-place, back/forth, up/down, and in-place matching tempo stepping tests. The number of steps, stance time, single and double support times (for in-place, back/forth, and up/down stepping) and difference between the metronome sound and grounding time (for matching tempo stepping) were evaluated. Reliabilities were high in almost all stepping tests (ICC=0.64~0.92). Correlations between stance time and double support time were high in back/forth and up/down stepping tests (r>0.83), as were correlations of number of steps, stance time, and single and double support times between back/forth and up/down stepping tests (r=0.72~0.84). The back/forth stepping and matching tempo stepping at 44 and 132 bpm tests and the stance and double support times in the former test are useful evaluation parameters of dynamic balance.