Effects of Motor-Cognitive Dual-Task Standing Balance Exergaming Training on Healthy Older Adults' Standing Balance and Walking Performance.

Objective: This study examined the effects of motor-cognitive dual-task exergaming standing balance training on healthy older adults' static, dynamic, and walking balance. Methods: Twenty-four adults older than 70 years (control group: n = 9, males = 6, balance training group: n = 15, males = 8) completed the experiment. Dual-tasking standing balance training comprised the accurate control of a ping-pong ball on a tray held with both hands, while standing on one leg (analog training) and three modules of Wii Fit™ exergaming (digital training). The duration of balance training was ∼15 minutes per day, 2 days per week for 8 weeks, in total 16 sessions. We measured one-leg standing time, functional reach distance, walking balance evaluated by the distance walked on a narrow beam (4-cm long, 4-cm wide, and 2-cm high) with single and dual tasking, habitual and maximal walking speed, and muscle strength of the hip extensor, hip abductor, hip adductor, knee extensor, and plantarflexor muscle groups in the right leg at baseline and after 8 weeks. Results: Control group decreased, but balance training group increased one-leg standing time. Only the balance training group improved functional reach distance and hip and knee extensor strength. There was no change in walking speed and walking balance in either group. In the balance training group, changes in maximal speed correlated with changes in dual-tasking walking balance and changes in one-leg standing time correlated with changes in single-tasking walking balance. Conclusion: These results suggest that 16 sessions of motor-cognitive dual-task standing exergaming balance training substantially improved healthy older adults' static and dynamic balance and leg muscle strength but failed to improve walking speed and walking balance. Balance exercises specific to walking balance need to be included in balance training to improve walking balance.

Cognitive dual-tasking augments age-differences in dynamic balance quantified by beam walking distance: A pilot study.

There is currently no test to directly and easily measure dynamic balance during walking in old adults. We examined the idea that distance of beam walking with and without cognitive dual-tasking could detect age differences in dynamic balance. Healthy old (n = 16, 71.2 y) and young (n = 20, 22.0 y) volunteers walked 3 times on 4-m long beams first without (single-tasking) then with a calculation task (dual-tasking) in order of decreasing beam width (12, 8, 4 cm). There was a Group (old, young) by Beam width (4, 8, 12 cm) by Task (single-, dual-tasking) interaction (F = 4.0, p = 0.026) for beam walking distance (primary outcome). Beam walking distance decreased similarly with decreasing beam width while single-tasking (12 cm: 3.88 m, 8 cm: 3.62 m, 4 cm: 2.49 m) and dual-tasking (12 cm: 3.87 m, 8 cm: 3.76 m, 4 cm: 2.59 m) in young adults. Beam walking distance decreased substantially and most on the narrowest beam while single-tasking (12 cm: 3.85 m, 8 cm: 3.72 m, 4 cm: 1.46 m) but decreased even more on the two narrowest beams during dual-tasking (12 cm 3.91 m, 8 cm: 2.63 m, 4 cm: 0.66 m) in old adults. Video analyses revealed that step length decreased in young while both step number and step length decreased in old adults. Beam width but not dual-tasking affected young adults' beam walking distance whereas both beam width and dual-tasking affected substantially and interactively old adults' beam walking distance and velocity. The results suggest that, if validated and cognitive performance also quantified, beam walking distance and walking velocity in single- and dual-tasking conditions could be a diagnostic tool of walking balance and cognitive impairment in aging.

Lower extremity power training improves healthy old adults' gait biomechanics.

PURPOSE: Age-related slowing of gait speed predicts many clinical conditions in later life. We examined the kinematic and kinetic mechanisms of how lower extremity power training increases healthy old adults' gait speed. METHODS: We randomly allocated old adults to a training (age 74.3 y, 9 males, 6 females) and a control group (age 73.6 y, 3 males, 4 females) and compared the biomechanics of habitual and fast gait before and after 16 sessions (8 weeks) of lower extremity power training. RESULTS: Training increased maximal leg press load by ∼40% (P < 0.05) and maximal voluntary force in five groups of leg muscles by ∼32% (P < 0.05) in the training group. Training vs. control tended to increase habitual (10.8 vs. 7.6%) and fast gait speed (17.6 vs. 9.0%; all P < 0.05) more. In the training group only, these increases in gait speed correlated with increases in stride length (habitual: r2 = 0.84, fast: r2 = 0.89). Training made old adults' gait more erect: hip and knee extension increased in the stance phase of gait. Training increased ankle joint positive work by 3.3 J (control: -0.4 J, Group by Time interaction: P < 0.05), which correlated r2 = 0.58 and r2 = 0.67 with increases in habitual and fast gait speed without changes in hip and knee joint powers. CONCLUSION: Increases in leg muscle power increased healthy old adults' gait speed through correlated increases in stride length and ankle plantarflexor work generation.

A Japanese Stretching Intervention Can Modify Lumbar Lordosis Curvature.

STUDY DESIGN: Eighteen healthy male adults were assigned to either an intervention or control group. OBJECTIVES: Isogai dynamic therapy (IDT) is one of Japanese stretching interventions and has been practiced for over 70 years. However, its scientific quantitative evidence remains unestablished. The objective of this study was to determine whether IDT could modify lumbar curvature in healthy young adults compared with stretching exercises used currently in clinical practice. SUMMARY OF BACKGROUND DATA: None of previous studies have provided data that conventional stretching interventions could modify spinal curvatures. However, this study provides the first evidence that a specific form of a Japanese stretching intervention can acutely modify the spinal curvatures. METHODS: We compared the effects of IDT, a Japanese stretching intervention (n=9 males), with a conventional stretching routine (n=9 males) used widely in clinics to modify pelvic tilt and lumbar lordosis (LL) angle. We measured thoracic kyphosis (TK) and LL angles 3 times during erect standing using the Spinal Mouse before and after each intervention. IDT consisted of: (1) hip joint correction, (2) pelvic tilt correction, (3) lumbar alignment correction, and (4) squat exercise stretch. The control group performed hamstring stretches while (1) standing and (2) sitting. RESULTS: IDT increased LL angle to 25.1 degrees (±5.9) from 21.2 degrees (±6.9) (P=0.047) without changing TK angle (pretest: 36.8 degrees [±6.9]; posttest: 36.1 degrees [±6.5]) (P=0.572). The control group showed no changes in TK (P=0.819) and LL angles (P=0.744). CONCLUSIONS: IDT can thus be effective for increasing LL angle, hence anterior pelvic tilt. Such modifications could ameliorate low back pain and improve mobility in old adults with an unfavorable pelvic position.

A behavioral mechanism of how increases in leg strength improve old adults' gait speed.

We examined a behavioral mechanism of how increases in leg strength improve healthy old adults' gait speed. Leg press strength training improved maximal leg press load 40% (p = 0.001) and isometric strength in 5 group of leg muscles 32% (p = 0.001) in a randomly allocated intervention group of healthy old adults (age 74, n = 15) but not in no-exercise control group (age 74, n = 8). Gait speed increased similarly in the training (9.9%) and control (8.6%) groups (time main effect, p = 0.001). However, in the training group only, in line with the concept of biomechanical plasticity of aging gait, hip extensors and ankle plantarflexors became the only significant predictors of self-selected and maximal gait speed. The study provides the first behavioral evidence regarding a mechanism of how increases in leg strength improve healthy old adults' gait speed.