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• Interactive stepping exercise is a feasible and effective intervention in elderly. • Interactive stepping exercise may improve executive function. • Interactive stepping exercise may improve gait variability. Recently, the interactive stepping exercise (ISE) was developed on the basis of square stepping exercise. The aim of this study was to examine the feasibility and effectiveness of ISE on executive function and gait variability among community-dwelling older adults. Fourteen participants were recruited and randomly assigned to the experimental group (n=7) or control group (n=7) and received ISE or home exercise program, respectively, three times a week for 12 weeks. The outcomes included retention rate, attendance rate, Trail Making Test, and dual-task walking. The results showed that participants had high retention and attendance rate for the ISE intervention. Moreover, significant improvement in the part A of Trail Making Test and stride length variability during cognitive dual-task walking after 12-week ISE intervention. The current results suggested that ISE is a feasible and effective intervention on executive function and gait variability in community-dwelling older adults. [ABSTRACT FROM AUTHOR]

Humans must maintain head and trunk stability while walking. The purpose of this study was to compare the kinematics of healthy controls and patients with vestibular hypofunction (VH) when walking and making head rotations of different frequencies in both light and dark conditions. We recruited eight individuals with VH and nine healthy control subjects to perform four tasks at their preferred gait speed, being normal walk, walking and making yaw head rotations at 1.5 Hz and 2 Hz, and walking in the dark and making yaw head rotations at 1.5 Hz. Linear kinematics as well as head, trunk, and pelvis angular velocities were captured using the Vicon motion analysis system (Vicon Motion Systems, Oxford, UK). We found no difference in walking velocities for any of the four walking conditions across groups. The lateral displacement of the center of mass was increased in VH patients. In the dark, patients had more head instability in pitch (larger amplitudes and velocities) even though they were walking and making active yaw head rotations. Patients also had a smaller relative phase angle (mean 3.50 ± standard deviation 2.13°) than controls (mean 10.31 ± standard deviation 2.70°) (p < 0.01). Our data suggest that patients with VH have difficulty walking with a straight trajectory when turning their head. Additionally, patients with VH have an abnormal excursion of spontaneous pitch head rotation while walking and making active yaw head turns, which is dependent on vision. Rehabilitation for these patients should consider applying unique head rotation frequencies when training gait with head turns as well as alternating their exposure to light. [ABSTRACT FROM AUTHOR]

Abstract: Declined balance functions have adverse effects on elderly population. Lower limbs muscle power training is currently an emerging concept in rehabilitation on individuals with decreased balance and mobility. In this prospective, controlled study, we used a human–computer interactive video-game-based rehabilitation device (LLPR) for training of lower limb muscle power in the elderly. Forty (aged>65years) individuals were recruited from the community. Twenty participants in the exercise group received 30-min training, twice a week, using the LLPR system. The LLPR system allows participants to perform fast speed sit-to-stand (STS) movements. Twenty age-matched participants in the control group performed slow speed STS movements, as well as strengthening and balance exercises, with the same frequency and duration. The results were compared after 12 sessions (6weeks) of training. The mechanical and time parameters during STS movement were measured using the LLPR system. Modified falls efficacy scale (MFES), Tinetti Performance-Oriented Mobility Assessment (POMA), function reach test, five times sit to stand (FTSS) and Timed Up and Go (TUG) were administered to participants as clinical assessments. Results showed that in the exercise group, all the mechanical and time parameters showed significant improvement. In control group, only the maximal vertical ground reaction force (MVGRF) improved significantly. For clinical assessments (balance, mobility, and self-confidence), exercise group showed significantly better scores. The STS movements in video-game-based training mimic real life situations which may help to transfer the training effects into daily activities. The effectiveness of lower limb muscle training is worthy of further investigation. [Copyright &y& Elsevier]

Abstract: In recent years, degenerative spinal instability has been effectively treated with a cage. However, little attention is focused on the design concept of the cage. The purpose of this study was to develop a new cage and evaluate its biomechanical function using a finite element method (FEM). This study employed topology optimization to design a new cage and analyze stress distribution of the lumbar spine from L1 to L3 with a new cage by using the commercial software ANSYS 6.0. A total of three finite element models, namely the intact lumbar spine, the spine with double RF cages, and with double new cages, were established. The loading conditions were that 10Nm flexion, extension, lateral bending, and torsion, respectively, were imposed on the superior surface of the L1 vertebral body. The bottom of the L3 vertebral body was constrained completely. The FEM estimated that the new cage not only could be reduced to 36% of the volume of the present RF cage but was also similar in biomechanical performance such as range of motion, stress of adjacent disc, and lower subsidence to the RF cage. The advantage of the new cage was that the increased space allowed more bone graft to be placed and the cage saved material. The disadvantage was that stress of the new cage was greater than that of the RF cage. [Copyright &y& Elsevier]

Objective. To investigate wrist kinematic characterization at various wheelchair seat positions.Design. A comparative study using a repetitive measures design.Background. People who use wheelchairs often sit on pressure-relief cushions, increasing the seat height. Wrist kinematic properties during manual propulsion could be altered. Wrist kinematics from a clinical perspective has not been previously investigated. This study characterizes wrist kinematic performance of subjects during manual wheelchair propulsion at various seat positions.Methods. Subjects for this investigation were 11 people with disabilities who use wheelchairs. Combinations of horizontal positions of the rear wheel and vertical seat height were evaluated. Consecutive EMG, wrist joint angle, and trigger signals were collected.Results. Altered seat height resulted in significant changes to temporal phases and wrist kinematic parameters; however, altered horizontal seat position did not cause significant variations. For all seat positions investigated, wrist extensor and flexor EMG signals maintained a similar level of contraction.Conclusion. During wheelchair propulsion, seat height was found to be a critical factor affecting the temporal parameters of movement and wrist kinematic properties of the subjects. Wrist joint angles and wrist flexion–extension range of motion all varied according to seat height. Observations and statistical analysis of the results provided useful information; however, an ideal seat position was not indicated.RelevanceStudy results have enhanced our understanding of wheelchair design, and should aid in development of future designs. In addition, the results may provide a strategy for dealing with the onset of arm/wrist pain and the prevention of carpal tunnel syndrome and other soft tissue injuries in people who use wheelchairs. [Copyright &y& Elsevier]

Abstract: Degeneration in the neuromuscular system due to aging can affect daily activities that need to be controlled by bimanual coordination with both hands. However, little is known about the influence of aging on grip strength and bimanual coordination control between hands. The purpose of this study was to investigate the influence of aging on the maximum grip force output and capacity of coordination control of two hands. Ten healthy elderly and 21 young adults were recruited and asked to execute maximum grip force tests and bimanual coordination control tasks with reciprocal grasping, holding, and releasing of a dynamometer with both hands at three target force levels (10, 20 and 40% maximal voluntary contraction, MVC). Compared with the young group, the maximum grip force of the hands of the elderly group was significantly lower by 77.5% (p<0.05) and 71.1% (p<0.05) in the dominant and non-dominant hands, respectively. The elderly adults also displayed a significantly longer alternating time control in the dominant to non-dominant and non-dominant to dominant hands at the 20% MVC target force level (p<0.05). Aging reduces the maximum hand grip force output and the performance of bimanual coordination control of two hands, which may lead to difficulty with the execution of daily activities requiring both hands. [Copyright &y& Elsevier]

Abstract: Background and objective: This study was designed to establish the validity and reliability of a new device that measures bilateral shoulder and elbow range of motion (ROM) and grip force performance in vivo. A further aim was to investigate the control of inter-limb grip force coordination during isometric force-maintenance tasks. Validity of the ROM and grip force measurements was examined using a validated clinical goniometer and standard weights. Subjects: Twenty-one healthy adults (six female, 15 male; mean±standard deviation age=23.05±3.51) were recruited for this study. Design: All subjects were asked to perform tests to evaluate the validity and reliability of ROM, grip force maximum voluntary contraction (MVC) and coordination control measurements. Results: The ROM and grip force measurements were linearly correlated with criterion standards. For reliability testing, all of the intraclass correlation coefficient values were >0.99. The inter-limb grip force coordination control task showed that the force modulation timing during dominant-to-non-dominant hand transition was longer than the non-dominant-to-dominant hand transition (p <0.05). Conclusions: These results demonstrate that this device is valid and reliable when used to measure shoulder and elbow ROM and grip force of both hands. Isometric force-maintenance tasks also indicated changes in inter-limb grip force control. [Copyright &y& Elsevier]

Abstract: The purpose of this study was to examine the effects of age on active leg stiffness adjustment, electromyogram (EMG) activities and energy stored during eccentric and concentric phases in performing a maximal functional task involving stretch-shorten cycle. Ten young (24.3±2 years) and 10 old (68.6±5 years) healthy male subjects were filmed during maximal performance of counter movement jump (CMJ) and squat jump (SJ) on force plate. Integrated EMG (IEMG), ground reaction force (GRF), active leg stiffness, energy stored/returned and active work done by the muscles were compared between two groups on eccentric (ECC) and concentric (CON) phases of CMJ. The GRF, leg stiffness and energy stored in ECC and GRF, IEMG, energy returned and active work in CON were less in the elderly (p <0.05). These results demonstrate that the neuromuscular function of adjusting active stiffness, storing elastic energy and optimizing the performance may decrease with age during CMJ. [Copyright &y& Elsevier]

Background and objective Ankle motion and proprioception in multiple axis movements are crucial for daily activities. However, few studies have developed and used a multiple axis system for measuring ankle motion and proprioception. This study was designed to validate a novel ankle haptic interface system that measures the ankle range of motion (ROM) and joint position sense in multiple plane movements, investigating the proprioception deficits during joint position sense tasks for patients with ankle instability. Methods Eleven healthy adults (mean ± standard deviation; age, 24.7 ± 1.9 years) and thirteen patients with ankle instability were recruited in this study. All subjects were asked to perform tests to evaluate the validity of the ankle ROM measurements and underwent tests for validating the joint position sense measurements conducted during multiple axis movements of the ankle joint. Pearson correlation was used for validating the angular position measurements obtained using the developed system; the independent t test was used to investigate the differences in joint position sense task performance for people with or without ankle instability. Results The ROM measurements of the device were linearly correlated with the criterion standards (r = 0.99). The ankle instability and healthy groups were significantly different in direction, absolute, and variable errors of plantar flexion, dorsiflexion, inversion, and eversion (p < 0.05). Conclusions The results demonstrate that the novel ankle joint motion and position sense measurement system is valid and can be used for measuring the ankle ROM and joint position sense in multiple planes and indicate proprioception deficits for people with ankle instability. [ABSTRACT FROM AUTHOR]

We aimed to assess and compare kinetics and kinematic variables of bed turning ability using a mobility detection system in patients with and without chronic low back pain and to observe the impacts of the disease on bed turning kinetics and kinematics. Thirty-five patients with chronic low back pain were enrolled and compared to healthy controls (n = 34). Pain scores and disability level were assessed by Numeric Pain Rating Scale and the function questionnaires including Oswestry Disability Index and Roland Morris Disability Questionnaire. Bed turning ability was tested using the Mobile Detection System. Univariate and multivariate regression analysis were applied to compare the differences between groups. Patients with chronic low back pain had significantly lower turning over and back force/weight ratio (p < 0.001) than those healthy controls. Turning over time was significantly longer in patients with Numeric Rating Scale score 3 than in those with Numeric Rating Scale score 2 (p = 0.015). Turning over and back force were significantly higher in male patients and patients with higher BMI after adjusting BMI and sex, respectively (all p < 0.001). When turning back, chronic low back pain patients with Numeric Rating Scale scores of 3 had lower turning back force/weight ratio than those with Numeric Rating Scale scores of 2 (p = 0.014). Male patients had higher turning back force/weight ratio after adjusting pain score (p = 0.001). The novel Mobility Detection System can provide more objective assessments of bed turning kinetics and kinematics in patients with chronic low back pain. • Mobility Detection System provided objective assessments of bed turning kinematics. • Pain was associated with turn over time and time to reach peak pressure. • Sex and pain level were significantly associated with turning force/weight ratio. [ABSTRACT FROM AUTHOR]