This study examined time efficiency in wheelchair locomotive activities among four different wheelchairs propelled by elders with arms and/or legs. Sixteen elder manual wheelchair users propelled her/his own wheelchair and three wheelchairs (the main drive-axis wheels positioning in front, middle, and rear, respectively) in the test of seven wheelchair locomotive activities of daily living. A Mixed-Model ANOVA and Bonferroni post hoc test (p < .05) were employed to determine the time efficiency among four wheelchairs and three groups. The results demonstrated better time efficiency resulted from propelling the mid drive-axis and/or rear drive-axis wheelchairs; using arms and legs simultaneously propelling wheelchairs was more time efficient than using the arms or legs only in the selected locomotive activities.
Yong Tai Wang, Randy Bernard, Clint Cope, Li-Shan Chang, Weerawat Limroongreungrat and Stephen Sprigle
Edward R. Elder
Edwrad J. Elder and Nancy M. Helsley
Jay L. Alberts, Christopher M. Elder, Michael S. Okun and Jerrold L. Vitek
The aim of this study was to determine the effects of unilateral deep brain stimulation (DBS) on the control and coordination of grasping forces produced by Parkinson's disease (PD) patients. Ten advanced PD patients with unilateral DBS in the globus pallidus (GPi) or the subthalamic nucleus (STN) (5 patients in each group) performed a functional bimanual dexterous manipulation task. Experiments were performed in the “Off” medication state with DBS “On” and “Off.” DBS resulted in (a) significant clinical improvements, (b) greater maximum grip force for both limbs, (c) reduced movement time, and (d) bilateral coupling of grasping forces. There were no significant differences between the GPi and STN groups for any clinical or kinematic measures. DBS of the GPi and STN leads to an improvement in the motor functioning of advanced PD patients. Improvement in force-timing specification during DBS might allow PD patients to employ a feedforward method of force control.
Heather Anne Hayes, Nikelle Hunsaker, Sydney Y. Schaefer, Barry Shultz, Thomas Schenkenberg, Lara A. Boyd, Andrea T. White, Kenneth B. Foreman, Philip Dyer, Rebecca Maletsky and Leland E. Dibble
Deficits in sequence-specific learning (SSL) may be a product of Parkinson’s disease (PD) but this deficit could also be related to dopamine replacement. The purpose of this study was to determine whether dopamine replacement affected acquisition and retention of a standing Continuous Tracking Task in individuals with PD. SSL (difference between random/repeated Root Mean Square Error across trials) was calculated over 2 days of practice and 1 day of retention for 4 groups; 10 healthy young (HY), 10 healthy elders, 10 individuals with PD on, 9 individuals with PD off their usual dosage of dopamine replacement. Improvements in acquisition were observed for all groups; however, only the HY demonstrated retention. Therefore, age appeared to have the largest effect on SSL with no significant effect of medication. Additional research is needed to understand the influence of factors such as practice amount, task difficulty, and dopamine replacement status on SSL deficits during postural tasks.
George J. Salem, Sean P. Flanagan, Man-Ying Wang, Joo-Eun Song, Stanley P. Azen and Gail A. Greendale
Stepping activities when wearing a weighted vest may enhance physical function in older persons. Using 3 weighted-vest resistance dosages, this study characterized the lower-extremity joint biomechanics associated with stepping activities in elders. Twenty healthy community-dwelling older adults, ages 74.5 ± 4.5 yrs, performed 3 trials of forward step-up and lateral step-up exercises while wearing a weighted vest which added 0% body weight (BW), 5% BW, or 10% BW. They performed these activities on a force platform while instrumented for biomechanical analysis. Repeated-measures ANOVA was used to evaluate the differences in ankle, knee, and hip maximum joint angles, peak net joint moments, joint powers, and impulses among both steping activities and the 3 loading conditions. Findings indicated that the 5% BW vest increased the kinetic output associated with the exercise activities at all three lower-extremity joints. These increases ranged from 5.9% for peak hip power to 12.5% for knee extensor impulse. The application of an additional 5% BW resistance did not affect peak joint moments or powers, but it did increase the joint impulses by 4–11%. Comparisons between exercise activities, across the 3 loading conditions, indicated that forward stepping preferentially targeted the hip extensors while lateral stepping targeted the plantar flexors; both activities equally targeted the knee extensors. Weighted-vest loads of 5% and 10% BW substantially increased the mechanical demand on the knee extensors, hip extensors (forward stepping), and ankle plantar flexors (lateral stepping).
Guy C. Simoneau and David E. Krebs
The importance of momentum in compensating for elderly individuals’ strength deficits to achieve activities of daily living, such as rising from a chair has been demonstrated in earlier studies. Here we present a case-control study of three healthy “non-fallers” and two “frequent fallers.” All 5 elders were community-living and were tested in the gait laboratory. A four-camera Selspot system was used to obtain whole-body momentum from an 11-segment kinematic model. Ground reaction forces and kinematics were used to calculate lower extremity joint moments. With the exception of the whole-body’s angular momentum about the vertical axis, linear and angular momenta during gait were minimum during mid-single limb support and maximum near heel contact. Whole-body momentum values for individuals with a history of falls were similar to those measured in non-fallers. However, subjects with a history of falls had between 17 and 37% smaller maximum ankle and knee torque values than the subjects without a history of falls during ambulation, A comprehensive description of whole-body linear and angular momenta during steady-state gait in older individuals is presented. While whole-body momentum characteristics and magnitude were similar between fallers and non-fallers. the consequences of the lesser torque values in the fallers’ knees and ankles to generate and control this momentum warrant further investigation.
David E. Krebs, Peter H. Velyvis and Mark W. Rogers
This study examined the prevalence of protective stepping and accompanying preparatory postural responses associated with lateral weight transfer (WT) while subjects attempted to sustain stationary standing. The subjects were 92 healthy young and older adults and persons with vestibular hypo-function. Force platform and whole-body-motion recordings were used to evaluate the prevalence of stepping and WT responses during stationary standing (eyes open or closed) using a semi-tandem foot position. WT components were also evaluated for volitionally requested step initiation, and as a function of support base configuration and direction of stepping among younger subjects. Only 10% of trials by subjects with bilateral vestibular hypofunction (BVH) during semi-tandem standing with eyes closed were completed without a step, while 31% of subjects with UVH, 69% of healthy elders, and all young healthy subjects were able to stand for the entire 7-sec trials. WT responses always preceded volitional steps from a standard feet-parallel orientation but occurred in only 13% of the spontaneous steps. The prevalence of WT was influenced by the direction of volitional stepping from semi-tandem standing, but not by the initial standing width. Spontaneous stepping to maintain standing balance is a naturally occurring and prevalent behavior among older adults and persons with vestibular hypo-function during tests of quasi-static standing. Differences between volitional and spontaneous step initiation involving the prevalence of preparatory lateral WT are a complex function of motor planning, mechanical constraints, and functional context.
Amandda de Souza, Cristiano Gomes Sanchotene, Cristiano Moreira da Silva Lopes, Jader Alfredo Beck, Affonso Celso Kulevicz da Silva, Suzana Matheus Pereira and Caroline Ruschel
Ther Today . 2000 ; 5 ( 4 ): 34 – 35 . doi:10.1123/att.5.4.34 10.1123/att.5.4.34 10. McKenney K , Elder AS , Elder C , Hutchins A . Myofascial release as a treatment for orthopaedic conditions: a systematic review . J Athl Train . 2013 ; 48 ( 4 ): 522 – 527 . 23725488 doi:10