Reliability of a new rapid step test for older women and its relationship with fall risk and leg muscle function

This study aimed to examine trial-to-trial reliability of a new clinical test, rapid reaction step cued on a screen test, and its relationship with fall risk score, independence in activity of daily living score, and various leg muscle function tests. One-hundred fifty seven older women participated in this study. Nine square plates (32 × 32 cm) were lined up with three plates. Participants stood on a center plate and were instructed to step, using one leg, to one of the other eight plates, as quickly as possible, when that plate changed in color from white to red. The mean total time and the mean total error time of rapid reaction step cued on a screen and, fall risk score, activity of daily living score, lower muscle function (isometric muscle strength: toe flexion, plantar flexion, knee extension, hip flexion;balance: one leg standing time with eye open, functional reach test;gait: 10 m walk time with maximal speed). Results: trial-to-trial reliabilities of step parameters were high (intraclass correlation coefficient [ICC] = 0.75 - 0.85). The step parameters correlated significantly with the other parameters except for toe flexion and hip flexion strengths. In conclusion, the present step test was found to evaluate physical function related to prevention of falls in older people.

Comparison of gait properties during level walking and stair ascent and descent with varying loads

This study aimed to compare gait properties during level walking and during stair ascent and descent with varying loads. Fifteen healthy young men (mean age: 22.1 ± 1.6 years) walked while holding four different loads relative to each subject’s body mass (0, 20, 40 and 60% of body mass: BM) on their backs. Stance time, swing time, and double support times were selected as gait parameters. All parameters showed a maximal value during stair ascent and a minimum value during level walking. Stance and double support times increased significan- tly with each load during level walking and during stair ascent and descent. In conclusion, st- air ascent and descent creates more unstable movement than level walking regardless of the weight of the load. The effect of loads on gait increases with the weight of the load and becomes obvious once the load exceeds 60% of BM.

Effect of Short-Term Whole-Body Vibration Training on Metabolic Risk Factors, Inflammatory Markers, and Arterial Stiffness

To investigate the effect of aerobic exercise combined with whole-body vibration (WBV) training on metabolic syndrome risk, and inflammatory markers, and to compare its effects on arterial stiffness and several blood parameters related to metabolic syndrome with those of aerobic training alone. Thirty healthy participants were divided into 2 groups matched for age and body mass index (BMI). Fifteen subjects were assigned to the WBV group (WBV + aerobic training) and the other 15 to the control group (aerobic training only). All participants performed a treadmill exercise 3 days/week for 4 weeks, for 50 min after 30 min rest period. Exercise was performed at a heart rate (HR) corresponding to 60% of the HR at each individual’s maximum oxygen uptake (VO2max). Body weight and BMI after training were significantly lower than those before training in the WBV group (P < 0.01). Concerning arterial stiffness, the pulse-wave velocity after training was significantly lower than that before training in the WBV group (1048.7 ± 105.6 vs. 1008.4 ± 101.1 cm/s, P < 0.05). Meanwhile, the VO2max after training was significantly higher than that before training in the WBV group (47.7 ± 12.8 vs. 51.4 ± 14.1 mL·min-1·kg-1, P < 0.01). However, no significant differences were observed in any parameters before and after training in the control group. Our results suggest that aerobic exercise combined with WBV training may be effective in reducing arterial stiffness and improving cardiorespiratory fitness than aerobic training alone.

Comparison of stepping parameters and center of foot pressure properties during different tempo stepping movements

This study was designed to examine the trial-to-trial reliability of stepping parameters and to compare the center of foot pressure (COP) when adapting to different tempos. Twenty healthy men (M age = 20.8, SD = 1.9 years) performed stepping tests to fixed tempos. The intra-class correlation coefficients of stepping and COP parameters were high (0.75 - 0.97). The time difference between foot contact time and fixed tempo and COP sway velocities of the X- and Y-axis were the largest at 40 beats per minute (bpm). At 60 and 120 bpm tempos, single support and swing times reflecting the stepping strategy correlated significantly with the root mean square and the velocity of the X-axis (r = I0.45 - 0.53I) . Because these step tempos are controlled largely by the automation of stepping, the single support and swing phases appeared to have a constant frequency. On the other hand, a stepping tempo of 40 bpm showed the largest sway velocity of X and Y and the smallest surrounding area mean path length. The above suggests that stepping at 40 bpm induced a larger sway area in relation to total path length and faster COP sway. Hence, it is inferred that the stepping task becomes more difficult at 40 bpm than at 60 and 120 bpm.

Muscular Contraction Ability Develops in the Lower Trapezius Muscle of the Dominant Arm in Team Hand-Ball Players

Eleven male university team hand-ball players (22 shoulders) with 5 or more years of competitive team hand-ball experience who had no history of injuries were included in this study. We compared the thickness of the trapezius muscle between their dominant arm and non-dominant arm, to clarify the correlation between the muscle thickness and muscular strength during internal and external rotation in the shoulder joints used to throw a handball. We measured the thickness of the middle and lower trapezius muscles at an abduction angle of 90&deg descending by the ultrasonic LOGIQ e and measured internal and external rotational muscular strength of the glenohumeral joint by BIODEX. The players showed significantly greater thickness of the lower trapezius muscle during constriction in the dominant arm than that in the non-dominant arm. Furthermore, a positive correlation was observed between muscle thickness of the lower trapezius muscle and the muscular strength during internal rotation of the glenohumeral joint. It is highly probable that the height of the constricting ability in the lower trapezius muscle in the dominant arm is related to the prevention of throwing injuries.

Erratum to “Muscular Contraction Ability Develops in the Lower Trapezius Muscle of the Dominant Arm in Team Hand-Ball Players” [Advances in Bioscience and Biotechnology 6 (2015) 368-374]

Eleven male university team hand-ball players (22 shoulders) with 5 or more years of competitive team hand-ball experience who had no history of injuries were included in this study. We compared the thickness of the trapezius muscle between their dominant arm and non-dominant arm, to clarify the correlation between the muscle thickness and muscular strength during internal and external rotation in the shoulder joints used to throw a handball. We measured the thickness of the middle and lower trapezius muscles at an abduction angle of 90° descending by the ultrasonic LOGIQ e and measured internal and external rotational muscular strength of the glenohumeral joint by BIODEX. The players showed significantly greater thickness of the lower trapezius muscle during constriction in the dominant arm than that in the non-dominant arm. Furthermore, a positive correlation was observed between muscle thickness of the lower trapezius muscle and the muscular strength during internal rotation of the glenohumeral joint. It is highly probable that the height of the constricting ability in the lower trapezius muscle in the dominant arm is related to the prevention of throwing injuries.

Erratum to “Muscular Contraction Ability Develops in the Lower Trapezius Muscle of the Dominant Arm in Team Hand-Ball Players” [Advances in Bioscience and Biotechnology Vol.6 No.5 (2015) 368-374]

Eleven male university team hand-ball players (22 shoulders) with 5 or more years of competitive team hand-ball experience who had no history of injuries were included in this study. We compared the thickness of the trapezius muscle between their dominant arm and non-dominant arm, to clarify the correlation between the muscle thickness and muscular strength during internal and external rotation in the shoulder joints used to throw a handball. We measured the thickness of the middle and lower trapezius muscles at an abduction angle of 90&deg descending by the ultrasonic LOGIQ e and measured internal and external rotational muscular strength of the glenohumeral joint by BIODEX. The players showed significantly greater thickness of the lower trapezius muscle during constriction in the dominant arm than that in the non-dominant arm. Furthermore, a positive correlation was observed between muscle thickness of the lower trapezius muscle and the muscular strength during internal rotation of the glenohumeral joint. It is highly probable that the height of the constricting ability in the lower trapezius muscle in the dominant arm is related to the prevention of throwing injuries.

Effects of hypoxic training on physiological exercise intensity and recognition of exercise intensity in young men

This study aimed to examine the effects of hypoxic training on physiological exercise intensity and recognition of exercise intensity in young men. The participants included 9 healthy young males (23.2 ± 6.5 years old, 176.2 ±6.7 cm, 74.3 ±16.4 kg). VO2 was measured during running with subjective exercise intensities of “somewhat hard” for 3 min and “fairly light” for 3 min. After the measurements, the participants answered the question “what percentage of your maximal effort was performed during both running exercises.” The exercise intensity recognition for the “fairly light” and “somewhat hard” intensities and the physiological exercise intensity measured by relative VO2 (%) and relative heart rate (HR, %) were then evaluated. The hypoxic training was performed 3 times a week for 4 weeks in a normobaric hypoxic chamber?(oxygen concentration, 15.4% and altitude, 2500 m). The participants ran at an exercise intensity of 60% VO2max for 40 min after a 5 min warm-up and then performed a 5 min cool-down. After training, they sat on a chair in the same room for 30 min. VO2max and HRmax changed significantly after the training. At “fairly light” intensity, the physiological measures were significantly higher than recognition of exercise intensity, with relative VO2 (%) increasing after training. In conclusion, hypoxia training causes an increase in VO2max and physiological exercise intensity during running at a “fairly light” intensity.

Effect of normobaric hypoxia on cardiorespiratory and metabolic risk markers in healthy subjects

The aims of this study were to investigate the influence of hypoxic physical exercise on metabolic risk markers and to compare the effects on maximum oxygen uptake (VO2max), arterial stiffness, and several blood parameters to a control group training under normoxic conditions. Eight healthy men were examined. Each participant performed exercise at a heart rate (HR) corresponding to 60% of the HR at VO2max on a treadmill device for 50 min (including 5 min warm-up and 5 min cool-down) after 30 min rest, on 3 days per week, for 4 weeks, in either normobaric hypoxia or normobaric normoxia. Each participant performed the exercise program under both environmental conditions with a wash-out period of 4 months. Brachial ankle pulse wave velocity after training was significantly lower in the hypoxic group than in the normoxic group (P = 0.02). The VO2max in the hypoxic group was significantly higher after than before training (P = 0.04). Our results suggest that hypoxic training may more effectively reduce arterial stiffness and improve cardiorespiratory function compared with training performed at the same relative exercise intensity under normoxic conditions.

Differences between Fallers by Tripping and Nonfallers in the OSFS Test

This study evaluates the effects of a fall experience caused by tripping during the repetitive stepping movements over an obstacle [obstacle-single leg forward step (OSFS) test]. The study included 147 participants who were divided into 2 groups: 25 fallers caused by tripping and 122 nonfallers. The subjects were asked to step forward over a 10-cm-high obstacle with 1 leg and then return to their original position, as quickly as possible, and this test was repeated for 5 times. The OSFS test was evaluated in 2 phases: the OSFS-F phase, wherein the participants stepped forward on one leg, and the OSFS-R phase, wherein they returned to their original position. Significant differences were observed in both phases of the OSFS test between the two groups, and the fallers by tripping were significantly inferior to the nonfallers. The area under the curve [AUC;area under the receiver operating characteristic (ROC) curve] was more than 0.63 for all the parameters, which was statistically significant. In conclusion, the fallers by tripping were inferior to the nonfallers in the obstacle step movement.

Relationships between gait properties on soft surfaces, physical function, and fall risk for the elderly

The plantar aspect change caused by contact with soft surfaces creates and unstable gait and increases the risk of falling, especially in the elderly. This study aimed to analyze gait property by three-dimensional motion analysis on soft and normal surfaces and to clarify the relationship with physical function and fall risk. Twenty-four older people aged 65-88 years old and living independently without any assistive device (7 men, 17 women) performed 5 m of walking with own maximal speed on normal and soft surface walkways. The soft surface walkway used was a low rebound urethane foam mattress. The three-dimensional kinematic gait analysis by sixteen anatomic points was used to evaluate gait property on both walkways. The gait property on soft surfaces tended to be swinging up and down in each joint and to largely lean left and right as compared with the normal surface. Moreover, it tended to decrease in a step length and to increase in a step width. All gait parameters on soft surfaces correlated significantly with functional reach. On the other hand, that on normal surface correlated significantly with leg strength. Gait properties on soft surfaces which changes in plantar aspect during foot contact differs from those on normal surfaces. Walking on soft surfaces may cause an unanticipated inverted pendulum sway supporting a foot contact point because of the disturbance by a sagging walkway;in short, requiring more effort to keep a body balanced. In conclusion, gait on the soft surfaces requires balance ability (functional reach) rather than leg strength.

The effects of fall experience by tripping on the movement of stepping over an obstacle

This study examines the effects of fall experience caused by tripping on the movement of stepping over an obstacle. The participants were divided into 3 groups (26 fallers caused by tripping, 24 fallers caused by other causes, and 145 non-fallers). Participants stepped forward over a 10 cm high obstacle with one leg, and then returned to their original position five times as quickly as possible. The OSFS (obstacle single leg forward step) test was measured in the following 2 phases: the OSFS-F phase, in which participants stepped out on one leg, and the OSFS-R phase, in which they returned it. Significant differences among the three groups were found in all parameters, and the fallers by tripping were significantly inferior to the non-fallers. There were no significant differences between the fallers by other reasons and the non-fallers in all parameters. The fallers by tripping were slower in the obstacle step movement than the non-fallers.