Search

Background and purpose Skill acquisition (ie, performance changes during practice) occurs in a nonlinear fashion. Despite this, motor learning is typically measured by comparing discrete timepoints. Thus, typical measures of motor learning do not detect skill acquisition characteristics that may be clinically meaningful. Reliable prediction of motor skill learning in people with Parkinson disease (PD) would allow therapists to more effectively individualize practice doses to fit specific patients' needs. The purposes of this study were to (a) characterize postural skill acquisition in people with PD, and identify factors (such as acquisition rate and practice dose to plateau) that predict learning, and (b) investigate whether levodopa medication (L-dopa) status during practice impacted learning. Methods Twenty-seven adults with PD practiced a postural motor task over 3 days, followed by 2 retention tests. Participants were randomized to practice either ON or OFF L-dopa. Data for repeating and random sequences were each analyzed using nonlinear curve-fitting and mixed-effects regressions. Learning was defined as pretest minus retention test performance. Results Participants with less physical impairment demonstrated less learning on the repeating and random sequence tasks compared with participants with more impairment. Participants who improved faster during practice demonstrated less learning on the repeating sequence task compared with participants who improved more slowly. Reaching plateau during practice was not related to learning. L-dopa did not impair learning. Discussion and conclusions Participants' skill acquisition characteristics were related to learning a postural motor task. Patient-specific factors, such as the rate of skill acquisition, level of physical function, and medication status, may influence how postural motor practice is delivered during balance rehabilitation.Video Abstract available for more insights from the authors (see the Video, Supplemental Digital Content 1, available at: http://links.lww.com/JNPT/A250).

BACKGROUND AND PURPOSE: Impaired gait, balance, and motor function are common in Parkinson disease (PD) and may lead to falls and injuries. Different forms of exercise improve motor function in PD, but determining which form of exercise is most effective requires a direct comparison of various approaches. In this prospective, controlled trial, we evaluated the impact of tango, treadmill walking, and stretching on gait, balance, motor function, and quality of life. We hypothesized tango and treadmill would improve forward walking and motor severity, and tango also would improve backward walking, balance, and quality of life. METHODS: Ninety-six participants (age: 67.2±8.9 years, 42% female) with mild to moderate idiopathic PD were serially assigned to tango, treadmill walking, or stretching (active control group) and attended one-hour classes twice weekly for 12 weeks. Assessments occurred off anti-PD medication before and after the intervention and at follow-up 12 weeks after the intervention. RESULTS: Forward velocity and backward velocity improved for the treadmill group from baseline to post-test and improvements persisted at follow-up. Backward velocity and motor functioning improved for the stretching group from baseline to post-test but results did not persist at follow-up. There were no significant changes in the tango group across time points. DISCUSSION AND CONCLUSIONS: Contrary to our hypotheses, only treadmill improved forward walking, while backward walking improved with treadmill and stretching. Future research should examine combinations of exercises with a focus on optimizing dosing and examining whether specific characteristics of people with PD correlate with different types of exercise. VIDEO ABSTRACT AVAILABLE: for more insights from the authors (see Video, Supplemental Digital Content 1)

Frequently, clinical balance outcome measures are limited by floor or ceiling effects and provide insufficient resolution to determine subtle deficits. Detailed assessment of postural control obtained through posturography may be cost-prohibitive or logistically infeasible in some clinical settings. Two-dimensional (2D) motion analysis may provide a clinically feasible means of obtaining detailed quantification of balance deficits. Forty-five participants aged 18-80 years, with and without Parkinson disease, performed the Push and Release (PR) test, sit-to-stand (STS), and timed single leg stance (SLS). Performance was captured simultaneously using a three-dimensional (3D) (10-camera laboratory-based 3D motion capture system and 3D motion analysis software) and 2D (two commercially available video cameras and 2D motion analysis software) system. Agreement was excellent between 2D and 3D systems for all outcomes of the PR and SLS (intraclass correlation coefficients [ICC2,1 ] 0.96-0.99, 95% CIs 0.92-0.98 to 0.99-1.0), and ranged from fair to excellent for STS outcomes (ICC2,1 0.59-0.93, 95% CIs 0.36-0.75 to 0.87-0.96). Test-retest reliability (ICC3,1 0.89-1.0, 95% CIs 0.76-0.96 to 1.0-1.0) and inter-rater reliability (ICC2,1 0.77-1.0, 95% CIs 0.61-0.87 to 1.0-1.0) of the 2D obtained outcomes were excellent. A technology package of commonly available video cameras and 2D motion analysis software was a valid and reliable method for quantifying outcomes of postural control tasks in people with a range of balance abilities. Two-dimensional analysis can be used in clinical practice to provide balance assessments as a cost-effective alternative to 3D motion capture. Anat Rec, 299:1165-1173, 2016. © 2016 Wiley Periodicals, Inc.

BACKGROUND:: Older adults often experience impaired mobility, lower extremity muscle weakness, and increased fall risk. Furthermore, when older adults perform tasks that require control of submaximal force, impairments in their ability to maintain steady and accurate force output have been reported. Such problems may be related to deteriorating levels of mobility, particularly in older adults who have fallen. PURPOSE:: The purpose of this study was to determine whether an association exists between muscle force steadiness (MFS) or muscle force accuracy (MFA) of the knee extensors and mobility in older adults who have fallen. METHODS:: Twenty older adults (x = 77.5 ± 7 years, 5 males and 15 females) with 2 or more comorbid conditions and who experienced a fall in the past year underwent assessment of maximal voluntary isometric contraction of the knee extensors. A submaximal target force of 50% of their maximal voluntary isometric contraction was used to determine concentric and eccentric (ECC) steadiness (the fluctuations in force production) and accuracy (the average distance of the mean force from the target force) measures. Mobility was indicated by the 6-minute walk test, the Timed Up and Go, stair ascent, and stair descent tests. Correlation analysis was used to assess the relationship between measures of muscle force control and mobility. RESULTS:: The correlations between muscle force steadiness and mobility were not significant (P >.05) for either contraction type. However, MFA during ECC contractions only was correlated significantly with all measures of mobility-6 minute walk test (r =-0.48; P =.03), Timed Up and Go (r = 0.68; P =.01), stair ascent (r = 0.60; P =.01), and stair descent (r = 0.75; P CONCLUSION:: The identification of the relationship between ECC MFA and mobility in older adults who have fallen is novel. Although the correlations are not causal, these relationships suggest that inaccurate force output during ECC contractions of the knee extensors is linked to impaired mobility. Language: en

Objectives To evaluate the impact of a single day of protective stepping practice in individuals with Multiple Sclerosis (MS). Background Multiple Sclerosis is a leading cause of disability among young adults in the United States. Gait and balance dysfunction are both widespread in MS and strong predictors of falls, disability, and quality of life among those with MS. Method Fourteen participants with MS and 11 neurotypical, age-matched control participants were exposed to repeated support surface perturbations over the course of 2 days: one “training” day and one “retention” day. Perturbations were elicited on an instrumented treadmill and marker data were collected to evaluate five outcomes (Margin of Stability, Step Length, Step Latency, Leg Angle, and Trunk Angle). Analytic Method Repeated measures data were analyzed using linear growth models and mixed effects models to evaluate the effects of group (MS or Control), trial, and the interaction of group by trial. Results Significant improvements in Step Length and Leg Angle and a trend for improvement in Margin of Stability among those with MS were observed. Step Latency and Trunk Angle did not show significant changes. Retention analyses revealed significant retention of improvements in Step Length and Leg Angle among MS participants. Discussion Protective step characteristics have been shown to be important predictors of fall risk in populations affected by neurological disorders. The present study indicates that these characteristics may be amenable to intervention through exposure to repeated, perturbations requiring protective stepping. Further research is needed to establish the predictive utility of these biomechanical markers for falls in MS specifically; however, the present findings suggest that perturbation training may be a valuable means of decreasing fall risk among those affected by MS.

Background. Individuals with unilateral vestibular hypofunction (UVH) alter their movement and reduce mobility to try to stabilize their gaze and avoid symptoms of dizziness and vertigo. Objective. To determine if individuals with UVH 6 weeks after surgery demonstrate altered head and trunk kinematics during community ambulation. Methods. A total of 15 vestibular schwannoma patients with documented postoperative unilateral vestibular loss and 9 healthy controls with symmetrical vestibulo-ocular reflexes participated in this cross-sectional study. Head kinematics (head turn frequency, amplitude, and velocity) and head-trunk coordination during community ambulation were obtained from inertial measurement units for all head movements and within specific amplitudes of head movement. Results. Individuals with UVH made smaller (mean 26° [SD = 3°] vs 32° [SD = 6°]), fewer (mean 133 [SD = 59] vs 221 [SD = 64]), and slower (mean 75°/s [SD = 8°/s] vs 103°/s [SD = 23°/s]) head turns than healthy individuals ( P < .05) but did not demonstrate significantly increased head-trunk coupling (mean 38% [SD = 18%] vs 31% [SD = 11%], P = .22). When small (≤45°) and large (>45°) head turns were considered separately, individuals with UVH demonstrated increased head-trunk coupling compared with healthy individuals for large head turns (mean 54% [SD = 23%] vs 33% [SD = 10%], P = .005). Conclusions. This study demonstrated that although walking at an adequate speed, individuals with UVH made fewer, smaller, and slower head movements symmetrically in both directions compared with healthy individuals and did not decouple their head movement relative to their trunk when required to make larger purposeful head turns during community ambulation.

© 2017, © The Author(s) 2017. Objectives: To determine whether 12-week home-based exergame step training can improve stepping performance, gait and complementary physical and neuropsychological measures associated with falls in Parkinson’s disease. Design: A single-blinded randomised controlled trial. Setting: Community (experimental intervention), university laboratory (outcome measures). Subjects: Sixty community-dwelling people with Parkinson’s disease. Interventions: Home-based step training using videogame technology. Main measures: The primary outcomes were the choice stepping reaction time test and Functional Gait Assessment. Secondary outcomes included physical and neuropsychological measures associated with falls in Parkinson’s disease, number of falls over six months and self-reported mobility and balance. Results: Post intervention, there were no differences between the intervention (n = 28) and control (n = 25) groups in the primary or secondary outcomes except for the Timed Up and Go test, where there was a significant difference in favour of the control group (P = 0.02). Intervention participants reported mobility improvement, whereas control participants reported mobility deterioration—between-group difference on an 11-point scale = 0.9 (95% confidence interval: −1.8 to −0.1, P = 0.03). Interaction effects between intervention and disease severity on physical function measures were observed (P = 0.01 to P = 0.08) with seemingly positive effects for the low-severity group and potentially negative effects for the high-severity group. Conclusion: Overall, home-based exergame step training was not effective in improving the outcomes assessed. However, the improved physical function in the lower disease severity intervention participants as well as the self-reported improved mobility in the intervention group suggest home-based exergame step training may have benefits for some people with Parkinson’s disease.

Background Falls are a significant burden for people with Parkinson’s disease (PD), however, individuals across the spectrum of disease severity respond differently to fall prevention interventions. Despite the multifactorial causes of falls in people with PD, recent work has provided insight into interventions that hold promise for fall prevention. Further, studies have begun to identify patient characteristics that may predict responsiveness to such interventions. Research question We discuss (i) the postural motor learning abilities of people with mild versus severe PD that could affect their ability to benefit from fall prevention interventions, (ii) how people with different severity of PD respond to such interventions, and (iii) the practical considerations of providing effective fall prevention interventions for people with PD across the spectrum of disease severity. Methods This narrative review consolidates recent work on postural motor learning and fall prevention rehabilitation involving exercise in people with PD. Results People with PD are able to improve postural motor control through practice, enabling them to benefit from exercise which challenges their gait and balance to reduce falling. Worsening of axial and cognitive symptoms may result in diminished learning, and those with more severe PD may require fully supervised, high intensity programs to reduce falls. Significance Understanding how people with PD across the spectrum of disease severity differ in their postural motor learning ability and response to different fall prevention interventions will enable researchers and clinicians to refine such interventions and their delivery to minimize falls and their negative sequelae in people with PD.

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.

Background Freezing of gait (FOG) is a relatively common and remarkably disabling impairment associated with Parkinson disease (PD). Laboratory-based measures indicate that individuals with FOG (PD + FOG) have greater balance deficits than those without FOG (PD − FOG). Whether such differences also can be detected using clinical balance tests has not been investigated. We sought to determine if balance and specific aspects of balance, measured using Balance Evaluation Systems Test (BESTest), differs between PD + FOG and PD − FOG. Furthermore, we aimed to determine if time-efficient clinical balance measures (i.e. Mini-BESTest, Berg Balance Scale (BBS)) could detect balance differences between PD + FOG and PD − FOG. Methods Balance of 78 individuals with PD, grouped as either PD + FOG ( n = 32) or PD − FOG ( n = 46), was measured using the BESTest, Mini-BESTest, and BBS. Between-groups comparisons were conducted for these measures and for the six sections of the BESTest using analysis of covariance. A PD composite score was used as a covariate. Results Controlling for motor sign severity, PD duration, and age, PD + FOG had worse balance than PD − FOG when measured using the BESTest ( p = 0.008, F = 7.35) and Mini-BESTest ( p = 0.002, F = 10.37), but not the BBS ( p = 0.27, F = 1.26). BESTest section differences were noted between PD + FOG and PD − FOG for reactive postural responses ( p F = 14.42) and stability in gait ( p = 0.003, F = 9.18). Conclusions The BESTest and Mini-BESTest, which specifically assessed reactive postural responses and stability in gait, were more likely than the BBS to detect differences in balance between PD + FOG and PD − FOG. Because it is more time efficient to administer, the Mini-BESTest may be the preferred tool for assessing balance deficits associated with FOG.

BackgroundDeclining ambulatory activity represents an important facet of disablement in Parkinson disease (PD).ObjectiveThe primary study aim was to compare the 2-year trajectory of ambulatory activity decline with concurrently evolving facets of disability in a small cohort of people with PD. The secondary aim was to identify baseline variables associated with ambulatory activity at 1- and 2-year follow-up assessments.DesignThis was a prospective, longitudinal cohort study.MethodsSeventeen people with PD (Hoehn and Yahr stages 1–3) were recruited from 2 outpatient settings. Ambulatory activity data were collected at baseline and at 1- and 2-year annual assessments. Motor, mood, balance, gait, upper extremity function, quality of life, self-efficacy, and levodopa equivalent daily dose data and data on activities of daily living also were collected.ResultsParticipants displayed significant 1- and 2-year declines in the amount and intensity of ambulatory activity concurrently with increasing levodopa equivalent daily dose. Worsening motor symptoms and slowing of gait were apparent only after 2 years. Concurrent changes in the remaining clinical variables were not observed. Baseline ambulatory activity and physical performance variables had the strongest relationships with 1- and 2-year mean daily steps.LimitationsThe sample was small and homogeneous.ConclusionsFuture research that combines ambulatory activity monitoring with a broader and more balanced array of measures would further illuminate the dynamic interactions among evolving facets of disablement and help determine the extent to which sustained patterns of recommended daily physical activity might slow the rate of disablement in PD.

Assessment of fall risk in an individual with Parkinson disease (PD) is a critical yet often time consuming component of patient care. Recently a simple clinical prediction tool based only on fall history in the previous year, freezing of gait in the past month, and gait velocity1.1 m/s was developed and accurately predicted future falls in a sample of individuals with PD.We sought to externally validate the utility of the tool by administering it to a different cohort of 171 individuals with PD. Falls were monitored prospectively for 6 months following predictor assessment.The tool accurately discriminated future fallers from non-fallers (area under the curve [AUC] = 0.83; 95% CI 0.76-0.89), comparable to the developmental study.The results validated the utility of the tool for allowing clinicians to quickly and accurately identify an individual's risk of an impending fall.

Falls are the leading cause of traumatic brain injury and fractures and the No. 1 cause of emergency department visits by older adults. Although declines in muscle strength and sensory function contribute to increased falls in older adults, skeletal muscle fatigue is often overlooked as an additional contributor to fall risk. In an effort to increase awareness of the detrimental effects of skeletal muscle fatigue on postural control, we sought to systematically review research studies examining this issue.The specific purpose of this review was to provide a detailed assessment of how anticipatory and reactive postural control tasks are influenced by acute muscle fatigue in healthy older individuals.An extensive search was performed using the CINAHL, Scopus, PubMed, SPORTDiscus, and AgeLine databases for the period from inception of each database to June 2013. This systematic review used standardized search criteria and quality assessments via the American Academy for Cerebral Palsy and Developmental Medicine Methodology to Develop Systematic Reviews of Treatment Interventions (2008 version, revision 1.2, AACPDM, Milwaukee, Wisconsin).A total of 334 citations were found. Six studies were selected for inclusion, whereas 328 studies were excluded from the analytical review. The majority of articles (5 of 6) utilized reactive postural control paradigms. All studies incorporated extrinsic measures of muscle fatigue, such as declines in maximal voluntary contraction or available active range of motion. The most common biomechanical postural control task outcomes were spatial measures, temporal measures, and end-points of lower extremity joint kinetics.On the basis of systematic review of relevant literature, it appears that muscle fatigue induces clear deteriorations in reactive postural control. A paucity of high-quality studies examining anticipatory postural control supports the need for further research in this area. These results should serve to heighten awareness regarding the potential negative effects of acute muscle fatigue on postural control and support the examination of muscle endurance training as a fall risk intervention in future studies.

Background. Although functional task-specific training is a viable approach for upper extremity neurorehabilitation, its appropriateness for older populations is unclear. If task-specific training is to be prescribed to older adults, it must be efficacious and feasible, even in patients with cognitive decline due to advancing age. Objective. This cross-sectional study tested the efficacy and feasibility of upper extremity task-specific training in older adults, including those with lower cognitive scores. Methods. Fifty older adults (age 65-89 years) without any confounding neuromuscular impairment were randomly assigned to a training group or no-training group. The training group completed 3 days (dosage = 2250 repetitions) of a functional upper extremity motor task (simulated feeding) with their nondominant hand; the no-training group completed no form of training at all. Both groups’ task performance (measured as trial time) was tested at pre- and posttest, and the training group was retested 1 month later. Efficacy was determined by rate, amount, and retention of training-related improvement, and compared across levels of cognitive status. Feasibility was determined by participants’ tolerance of the prescribed training dose. Results. The training group was able to complete the training dose without adverse responses and showed a significant rate, amount, and retention of improvement compared with the no-training group. Cognitive status did not alter results, although participants with lower scores on the Montreal Cognitive Assessment were slower overall. Conclusions. Task-specific training may be appropriate for improving upper extremity function in older adults, yet future work in older patients with specific neurological conditions is needed.

Importance Individuals with vestibular hypofunction acutely restrict head motion to reduce symptoms of dizziness and nausea. This restriction results in abnormal decoupling of head motion from trunk motion, but the character, magnitude, and persistence of these deficits are unclear. Objective To use wearable inertial sensors to quantify the extent of head and trunk kinematic abnormalities in the subacute stage after resection of vestibular schwannoma (VS) and the particular areas of deficit in head-trunk motion. Design, Setting, and Participants This cross-sectional observational study included a convenience sample of 20 healthy adults without vestibular impairment and a referred sample of 14 adults 4 to 8 weeks after resection of a unilateral VS at a university and a university hospital outpatient clinic. Data were collected from November 12, 2015, through November 17, 2016. Exposures Functional gait activities requiring angular head movements, including items from the Functional Gait Assessment (FGA; range, 1-30, with higher scores indicating better performance), the Timed Up & Go test (TUG; measured in seconds), and a 2-minute walk test (2MWT; measured in meters). Main Outcomes and Measures Primary outcomes included peak head rotation amplitude (in degrees), peak head rotation velocity (in degrees per second), and percentage of head-trunk coupling. Secondary outcomes were activity and participation measures including gait speed, FGA score, TUG time, 2MWT distance, and the Dizziness Handicap Inventory score (range, 0-100, with higher scores indicating worse performance). Results A total of 34 participants (14 men and 20 women; mean [SD] age, 39.3 [13.6] years) were included. Compared with the 20 healthy participants, the 14 individuals with vestibular hypofunction demonstrated mean (SD) reduced head turn amplitude (84.1° [15.5°] vs 113.2° [24.4°] for FGA-3), reduced head turn velocities (195.0°/s [75.9°/s] vs 358.9°/s [112.5°/s] for FGA-3), and increased head-trunk coupling (15.1% [6.5%] vs 5.9% [5.8%] for FGA-3) during gait tasks requiring angular head movements. Secondary outcomes were also worse in individuals after VS resection compared with healthy individuals, including gait speed (1.09 [0.27] m/s vs 1.47 [0.22] m/s), FGA score (20.5 [3.6] vs 30.0 [0.2]), TUG time (10.9 [1.7] s vs 7.1 [0.8] s), 2MWT (164.8 [37.6] m vs 222.6 [26.8] m), and Dizziness Handicap Inventory score (35.4 [20.7] vs 0.1 [0.4]). Conclusions and Relevance With use of wearable sensors, deficits in head-trunk kinematics were characterized along with a spectrum of disability in individuals in the subacute stage after VS surgery compared with healthy individuals. Future research is needed to fully understand how patterns of exposure to head-on-trunk movements influence the trajectory of recovery of head-trunk coordination during community mobility.

A consequence of vestibular loss is increased coupling of head-on-trunk motion, particularly in the yaw plane, which adversely affects community mobility in these patients. Inertial sensors may provide a means of better understanding normal decoupling behaviors in community environments, but demonstration of their validity and responsiveness is needed. This paper examined the validity and measurement sensitivity of inertial sensors in quantifying yaw plane head-trunk decoupling during unrestricted and restricted cervical motion conditions in healthy adults. Peak head turn amplitude and velocity, head-trunk coupling, and trunk turn lag were simultaneously measured using wearable inertial sensors and a motion capture system. Agreement between motion capture and the inertial sensors was excellent (intraclass correlation coefficients(2,1) >.75) for all measured outcomes during a static head turn task and for peak head turn velocity and trunk turn lag during a walking task. Cervical collar use significantly reduced head turn amplitude and velocity, and increased coupling of head-on-trunk motion (p

Decreased reactive postural responses in elderly adults may place them at increased risk for falls and related injuries. The first step in addressing the high rate of falls in the elderly population is to determine a baseline for postural response in healthy young and healthy elderly individuals. To determine these age-related differences in reactive postural responses during recovery from posterior and anterior perturbations, we used the tether-release method in conjunction with a motion analysis system to evaluate overall movement latencies, overall movement amplitude and velocity, and joint-specific amplitude and velocity in healthy young (n = 10, mean age=25 ± 5) and healthy elderly participants (n = 10, mean age = 67 ± 6). During posterior perturbations, healthy elderly participants had increased recovery time (P = 0.01) and ratio of center of mass to step length (P = 0.013) when compared with young participants. Elderly participants also had decreased step length (P = 0.006), peak COM velocity (P = 0.01), peak knee flexion angle (P = 0.002), and decreased hip (P = 0.005) and knee (P = 0.0005) average angular velocity when compared with young participants. We conclude that these movement deficiencies at the hip and knee limited the length of the recovery step. With this restricted step, elderly participants could not achieve adequate mechanical advantage to counteract the displacement of their COM using a single step. During anterior perturbations, elderly participants did not exhibit any significant differences compared to young participants in overall movement variables. This understanding of postural responses in healthy individuals is clinically relevant to the development of rehabilitation programs for individuals at high fall risk.

BACKGROUND AND PURPOSE:: The sensory and motor deficits associated with multiple sclerosis (MS) contribute to falls with the majority of persons with MS falling at least once annually. To appropriately direct treatment, accurate fall prediction measures are needed. In this study of community-dwelling individuals with MS followed for 12 months, we sought to determine frequency of falls, utility of clinical balance tests to predict falls, and accuracy of participants' retrospective recall of fall events. METHODS:: Independently ambulatory persons with MS underwent 5 clinical balance tests including Activities-specific Balance Confidence, Berg Balance Scale, Functional Reach, Timed Up and Go, and Dynamic Gait Index, and one disease-specific measure of disability (Expanded Disability Status Scale) and then were followed for 1 year. Participants were queried monthly by phone to determine the number of fall events that had occurred. Accuracy of fall prediction was determined by receiver operating characteristic curve analysis and comparison of balance test performance between fallers and nonfallers. RESULTS:: Sixty-one percent of the 38 participants were classified as fallers at 12-month follow-up. Only the Berg Balance Scale, Dynamic Gait Index, and the Activities-specific Balance Confidence demonstrated clinically useful levels of accuracy. In addition, participants were generally poor in their accurate recall of fall events relative to their monthly fall reports. DISCUSSION AND CONCLUSIONS:: The majority of participants fell during a 1-year prospective follow-up. Only 2 balance performance measures and 1 balance confidence measure accurately distinguished between fallers and nonfallers as well as possessed clinically useful levels of sensitivity and specificity. These results also emphasized the inaccuracy of retrospective fall history in an MS sample.Video Abstract available (see Supplemental Digital Content 1, http://links.lww.com/JNPT/A55) for more insights from the author. Language: en

Despite the common complaints of dizziness and demyelination of afferent or efferent pathways to and from the vestibular nuclei which may adversely affect the angular vestibulo-ocular reflex (aVOR) and vestibulo-spinal function in persons with multiple sclerosis (PwMS), few studies have examined gaze and dynamic balance function in PwMS. (1) Determine the differences in gaze stability, dynamic balance and participation measures between PwMS and controls, (2) Examine the relationships between gaze stability, dynamic balance and participation. Nineteen ambulatory PwMS at fall-risk and 14 age-matched controls were recruited. Outcomes included (1) gaze stability (angular aVOR gain [ratio of eye to head velocity]; number of compensatory saccades [CS] per head rotation; CS latency; gaze position error; coefficient of variation [CV] of aVOR gain), (2) dynamic balance (functional gait assessment, FGA; four square step test), and (c) participation (dizziness handicap inventory; activities-specific balance confidence scale). Separate independent t-tests and Pearson's correlations were calculated. PwMS were age = 53 ± 11.7 years and had 4.2 ± 3.3 falls/year. PwMS demonstrated significant (P 0.05) impairments in gaze stability, dynamic balance and participation measures compared to controls. CV of aVOR gain and CS latency were significantly correlated with FGA. Deficits and correlations across a spectrum of disability measures highlight the relevance of gaze and dynamic balance assessment in PwMS. Anat Rec, 301:1852-1860, 2018. © 2018 Wiley Periodicals, Inc.

We determined the number of days required, and whether to include weekdays and/or weekends, to obtain reliable measures of ambulatory physical activity in people with Parkinson's disease (PD). Ninety-two persons with PD wore a step activity monitor for seven days. The number of days required to obtain a reliable estimate of daily activity was determined from the mean intraclass correlation (ICC2,1) for all possible combinations of 1-6 consecutive days of monitoring. Two days of monitoring were sufficient to obtain reliable daily activity estimates (ICC2,1 > 0.9). Amount (p = 0.03) but not intensity (p = 0.13) of ambulatory activity was greater on weekdays than weekends. Activity prescription based on amount rather than intensity may be more appropriate for people with PD.

Background Physical therapists treat older individuals, characterized as both a needy and expanding population. Frailty, a predisability condition with links to chronic inflammatory conditions, is estimated to affect 7% of individuals older than 60 years and 40% of people older than 80 years. Chronic inflammation is one of the most important physiologic correlates of the frailty syndrome and high levels of proinflammatory cytokines, related to both aging and increasing adiposity in older individuals are related to an increased risk of mortality, sarcopenia, reduced muscle strength and decreased mobility. Purpose The purpose of this narrative review is to inform the physical therapist of the effects of aging and increasing adiposity on chronic inflammation and the association of inflammation with muscle loss, strength, and mobility impairments in older adults; and to review the current evidence to provide clinical recommendations on physical activity and exercise regimes that may mitigate chronic inflammation in older adults. Discussion As physical therapists help manage and treat an increasingly older population, understanding how the inflammatory milieu changes with aging and increasing adiposity and how these changes can be impacted by physical therapists via exercise and physical activity is critical. Conclusion Exercise is a potent preventive intervention strategy and countermeasure for chronic inflammation and adiposity. Exercise can also benefit the frail older individual by combating the negative effects of chronic inflammation and optimally balancing the production of pro and anti-inflammatory cytokines. In addition to providing an anti-inflammatory environment within muscle to mitigate the effects of chronic inflammation, exercise has the added benefit of improving muscle mass and function and decreasing adiposity in older adults.

To examine fall risk trajectories occurring naturally in a sample of individuals with early to middle stage Parkinson disease (PD).Latent class analysis, specifically growth mixture modeling (GMM), of longitudinal fall risk trajectories.Assessments were conducted at 1 of 4 universities.Community-dwelling participants with PD of a longitudinal cohort study who attended at least 2 of 5 assessments over a 2-year follow-up period (N=230).Not applicable.Fall risk trajectory (low, medium, or high risk) and stability of fall risk trajectory (stable or fluctuating). Fall risk was determined at 6 monthly intervals using a simple clinical tool based on fall history, freezing of gait, and gait speed.The GMM optimally grouped participants into 3 fall risk trajectories that closely mirrored baseline fall risk status (P=.001). The high fall risk trajectory was most common (42.6%) and included participants with longer and more severe disease and with higher postural instability and gait disability (PIGD) scores than the low and medium fall risk trajectories (P.001). Fluctuating fall risk (posterior probability0.8 of belonging to any trajectory) was found in only 22.6% of the sample, most commonly among individuals who were transitioning to PIGD predominance.Regardless of their baseline characteristics, most participants had clear and stable fall risk trajectories over 2 years. Further investigation is required to determine whether interventions to improve gait and balance may improve fall risk trajectories in people with PD.

Background The benefits of exercise for reducing disability in people with Parkinson disease (PD) are becoming more evident. Optimal benefit, however, requires regular and sustained participation. Factors associated with engaging in regular exercise have received little scientific scrutiny in people with PD. Objective The purpose of this study was to explore factors associated with exercise behavior in patients with PD using the International Classification of Functioning, Disability and Health (ICF) as a guiding framework. Design This was a cross-sectional study. Methods The participants in this study were 260 patients with PD from 4 institutions. Participants were designated as “exercisers” or “nonexercisers” based on responses to the Stages of Readiness to Exercise Questionnaire. Exercise status was validated using the Physical Activity Scale for the Elderly and an activity monitor. Factors potentially associated with exercise behavior included measures of body structure and function, activity, participation, environmental factors, and personal factors. Their relative contributions were analyzed using logistic regression and quantified with odds ratios. Results One hundred sixty-four participants (63%) were designated as exercisers. Participants with high self-efficacy were more than twice as likely to engage in regular exercise than those with low self-efficacy (adjusted odds ratio=2.34, 95% confidence interval=1.30–4.23). College educated and older participants also were more likely to exercise. Disabling influences of impairments, activity limitations, and participation restrictions were not associated with exercise behavior. Limitations The cross-sectional nature of the study limited the ability to make causal inferences. Conclusions Self-efficacy, rather than disability, appears to be strongly associated with whether ambulatory, community-dwelling people with PD exercise regularly. The results of this study suggest that physical therapists should include strategies to increase exercise self-efficacy when designing patient intervention programs for patients with PD.

). ( Background. A history of falls or imbalance may lead to a fear of falling, which may lead to self-imposed avoidance of activity; this avoidance may stimulate a vicious cycle of deconditioning and subsequent falls. Objective. The purpose of this study was to develop a questionnaire that would quantify avoidance behavior due to a fear of falling. Design. This study consisted of 2 parts: questionnaire development and psychometric testing. Questionnaire development involved an expert panel and 39 residents of an assisted living facility. Sixty-three community-dwelling individuals with various health conditions participated in psychometric testing. Method. Questionnaire development included the evaluation of face and content validity and factor analysis of the initial questionnaire. The final result of questionnaire development was the Fear of Falling Avoidance Behavior Questionnaire (FFABQ). In order to determine its psychometric properties, reliability and construct validity were assessed through administration of the FFABQ to participants twice, 1 week apart, and comparison of the FFABQ with other questionnaires related to fear of falling, functional measures of balance and mobility, and daily activity levels using an activity monitor. Results. The FFABQ had good overall test-retest reliability (intraclass correlation coefficient.812) and was found to differentiate between participants who were considered “fallers” (ie, at least one fall in the previous year) and those who were considered “nonfallers.” The FFABQ predicted time spent sitting or lying and endurance. Limitations. A relatively small number of people with a fear of falling were willing to participate. Conclusion. Results from this study offer evidence for the reliability and validity of the FFABQ and support the notion that the FFABQ measures avoidance behavior rather than balance confidence, self-efficacy, or fear.

Background Macromastia can be a morbid condition causing affected women to endure shoulder pain, back pain, intertrigo, and shoulder grooving from the bra straps. Subjective symptoms are effectively relieved by reduction mammaplasty surgery. Reliable objective evidence is limited in evaluating benefits for this patient population. Methods Eleven women undergoing reduction mammaplasty were evaluated before surgery and 3 months after surgery. Evaluation modeled maximal compressive forces at the low back during an unconstrained lifting task using inverse dynamics and measured the subjective level of disability using the Functional Rating Index. Results The analysis of the kinematic and kinetic data demonstrated no significant difference in ankle, knee, and hip joint angles between pretests and posttests. In addition, the average maximum low-back compressive forces decreased 35 percent for the unconstrained lifting task, and the Functional Rating Index scores improved 76 percent following surgery. Greatest improvement was reported for the frequency of pain and travel. Conclusion Reduction mammaplasty surgery produced objective improvement in low-back compressive forces and patients' reported level of functional disability.

Menopause is associated with both a loss of muscle mass and a worsening of insulin sensitivity (IS). Although eccentric resistance exercise (ECC) can effectively improve muscle mass over time, a single bout of ECC can worsen IS. This study assessed the effect of repeated ECC on IS, muscle mass, and function in postmenopausal women with impaired glucose tolerance (IGT).Sixteen PM women (aged 56 years +/- 6.4) with IGT were randomly assigned to a 12-week, knee extensor ECC program (n = 10) or a nonexercise control group (CON) (n = 6). Participants underwent hyperinsulinemic-euglycemic clamps, dual-energy x-ray (DEXA) absorptiometry, quadriceps strength assessment, 6-minute walk (6MW) tests, and an assessment of steps taken per day before and after training.ECC participants experienced greater increases in leg lean soft tissue mass (ECC, 0.41 kg; CON, -0.53 kg; p = 0.03), quadriceps strength (ECC, 9.3 kg force; CON, -2.9 kg force; p = 0.02), and 6MW distance (ECC, 56.4 meters; CON, 3.3 meters; p = 0.03) than CON participants and demonstrated a trend toward more steps taken per day posttraining (ECC, +1747 steps; CON, +339 steps; p = 0.10). IS was unchanged.This novel exercise improves muscle mass and function without worsening IS in postmenopausal women with IGT. Because it can be performed at low levels of exertion and improves muscle mass and function without impairing IS, ECC should be used to ameliorate muscle loss in physically inactive postmenopausal women. The impact of longer-term ECC on IS should be investigated. Demonstrating that ECC does not worsen IS in this population is significant because it has promise to combat the muscle-mediated impairments common in aging women.

Background: Novel interventions that can safely and effectively overload muscle early following anterior cruciate ligament reconstruction are needed to minimize atrophy and weakness that often becomes longstanding. Evidence Acquisition: Eccentrically induced forces can be safely applied during the early stages of rehabilitation following surgery and serve as a potent stimulus for increasing muscle size and strength. Results: Compared to a standard rehabilitation program, adding an early 12-week eccentric resistance-training program 3 weeks after anterior cruciate ligament reconstruction induces improvement in quadriceps and gluteus maximus volume at 15 weeks and at 1 year after surgery. Likewise, those who performed an eccentrically biased rehabilitation program also achieved greater improvements in quadriceps strength and hopping ability measured at 15 weeks and at 1 year after surgery. Clinical Relevance: There is potential to safely and feasibly perform eccentric contractions as part of a formal rehabilitation program following anterior cruciate ligament reconstruction.

PURPOSE Many older individuals have persistent quadriceps strength impairments after a total knee arthroplasty (TKA). A combination of muscle atrophy and neuromuscular activation deficits apparently contributes to residual strength impairments. The purpose of this short report is to describe the contribution of quadriceps muscle activation and muscle volume to impaired muscle strength in older individuals an average of 21 months following a TKA. METHODS Seventeen individuals (males: 3, females: 14; mean age: 68 yrs +/- 8.7; BMI: 33 +/- 4.8 kg/m2; number of TKA: 24; average postoperative months: 21 +/- 11.3) recruited from an orthopaedic surgeon's practice provided their written consent and participated in this study. Quadriceps strength (MVIC) and voluntary quadriceps muscle activation (QA) were measured with use of a burst-superimposition technique in which a supramaximal burst of electrical stimulation is superimposed on an MVIC. Quadriceps volume (QV) was assessed from magnetic resonance images of the quadriceps. RESULTS The mean quadriceps strength was 107.3 Nm +/- 36.4 (range: 43.22 - 205.2). The mean QA (as described with a central activation ratio) was 0.97 +/- 0.04 (range: 0.83 - 1.00). The mean QV was 1093 cm3 +/- 311.80 (range: 653.66 - 1706.56). QA and QV explain 85% of the variance in quadriceps strength (R2 = .85, p < 0.001), with QV having the greatest contribution to strength (R2 = .77, p < 0.001). CONCLUSIONS QV is a much stronger predictor of quadriceps strength than QA in individuals more than 1 year following TKA. Activation levels contributed little to strength one year following TKA, compared to its profound contribution in the first few postoperative months. Physical therapy interventions focused on improving muscle size in this population should be considered more relevant than countermeasures addressing neuromuscular activation.

Background:Novel interventions that can safely and effectively overload muscle early following anterior cruciate ligament reconstruction are needed to minimize atrophy and weakness that often becomes longstanding.Evidence Acquisition:Eccentrically induced forces can be safely applied during the early stages of rehabilitation following surgery and serve as a potent stimulus for increasing muscle size and strength.Results:Compared to a standard rehabilitation program, adding an early 12-week eccentric resistance-training program 3 weeks after anterior cruciate ligament reconstruction induces improvement in quadriceps and gluteus maximus volume at 15 weeks and at 1 year after surgery. Likewise, those who performed an eccentrically biased rehabilitation program also achieved greater improvements in quadriceps strength and hopping ability measured at 15 weeks and at 1 year after surgery.Clinical Relevance:There is potential to safely and feasibly perform eccentric contractions as part of a formal rehabilitation program following anterior cruciate ligament reconstruction.

Background Falls can cause moderate to severe injuries such as hip fractures and head trauma in older adults. While declines in muscle strength and sensory function contribute to increased falls in older adults, skeletal muscle fatigue is often overlooked as an additional contributor to fall risk. The purpose of this investigation was to examine the effects of acute lower extremity muscle fatigue and age on reactive postural control in healthy adults. Methods A sample of 16 individuals participated in this study (8 healthy older adults and 8 healthy young persons). Whole body kinematic and kinetic data were collected during anterior and posterior reproducible fall tests before (T0) and immediately after (T1) eccentric muscle fatiguing exercise, as well as after 15-min (T15) and 30-min (T30) of rest. Findings Lower extremity joint kinematics of the stepping limb during the support (landing) phase of the anterior fall were significantly altered by the presence of acute muscle fatigue. Step velocity was significantly decreased during the anterior falls. Statistically significant main effects of age were found for step length in both fall directions. Effect sizes for all outcomes were small. No statistically significant interaction effects were found. Interpretation Muscle fatigue has a measurable effect on lower extremity joint kinematics during simulated falls. These alterations appear to resolve within 15 min of recovery. The above deficits, coupled with a reduced step length, may help explain the increased fall risk in older adults.

Hypokinesia and bradykinesia as movement deficits of Parkinson disease are thought to be mediated by both basal ganglia dysfunction and a loss of muscle mass and strength commensurate with aging and decreased levels of physical activity. For these reasons, we sought to utilize resistance training as a means to increase muscle force and minimize hypokinesia and bradykinesia in persons with Parkinson disease and examine the effects of exercise and medication on Body Structure and Function (muscle force production and muscle cross-sectional area), Activity (mobility), and Participation (Health Status) outcomes.Forty-two participants were enrolled in a 12-week randomized clinical trial that compared 2 active exercise interventions: a standard care control group (Active Control) and an experimental group that underwent Resistance Exercise via Negative Eccentric Work (RENEW).Participants in both groups improved in muscle force production and mobility as a result of exercise and medication (P0.02). There were no significant interaction or between-group differences and no significant changes in muscle cross-sectional area or health status were observed. Effect sizes for exercise and medication combined exceeded the effect sizes of either intervention in isolation.Taken together, these results point to the complementary effects of exercise and medication on the Body Structure and Function and Activity outcomes but little effect on Participation outcomes.Video Abstract available for more insights from the authors (see Supplemental Digital Content 1, http://links.lww.com/JNPT/A92).

Background and Purpose. Postural control problems, falls, and fall-related injuries are a common source of morbidity in elderly individuals, especially those with Parkinson disease (PD). Clinical balance tests such as the Berg balance scale and the functional reach have been reported to be useful in assessing fall risk in elderly individuals. However, the utility of commonly used clinical balance tests as accurate screens for fall risk has not been sufficiently examined in persons with PD. The purposes of this study were to identify which commonly used clinical balance tests of persons with PD were predictive of falls, to re-examine the cutoff scores for these tests with the goal of maximizing sensitivity as well as minimizing the negative likelihood ratio, and to determine which of the clinical balance tests had the most value in predicting falls. Participants. Forty-five persons with a diagnosis of idiopathic PD, aged 39-90 years (mean [sd] =69.94 [11.28]; mean [sd] Hoehn and Yahr level = 2.60 [.66]) participated. Methods: Upon initial contact with participants, demographics and fall history were gathered and baseline physical examinations were performed. Each individual underwent balance testing with the functional reach test, the Berg balance scale, the dynamic gait index, timed up and go, and the cognitive timed up and go. Fallers and nonfallers were divided based on fall history and groups were compared on balance test performance. Sensitivity, specificity, likelihood ratios, and receiver operator characteristic curves were calculated for all balance tests. Results: Twenty-five (55%) participants had a history of falls. Using cut-off scores reported in previous studies, the sensitivity of all tests was low (less than 0.60) and the specificity was high (greater than 0.85). Reconsideration of the cut-off scores resulted in increased sensitivity for all tests (greater than 0.75) and low negative likelihood ratios (less then .30). Discussion and Conclusion: Given the large financial, psychological, and physical complications that are associated with a fall and relatively little harmful effects of fall prevention interventions, we propose consideration of cut-off scores that maximize sensitivity for individuals with PD. Regardless of the performance on any individual clinical balance test, the multifactorial nature of postural instability in PD may necessitate a battery of tests to provide the most accurate identification of fall risk. Language: en

Case report.To present a progressively increasing negative-work exercise program via eccentric ergometry early after anterior cruciate ligament reconstruction (ACL-R) and to suggest the potential of negative work to amplify the return of quadriceps size and strength.The patient was a 26-year-old highly active recreational athlete who sustained an ACL tear while skiing in January 2004 and then again while skiing in February 2005. This individual underwent an arthroscopically assisted ACL-R with a double-loop semitendinosusgracilis autograft initially, then a patellar tendon autograft following his ACL graft rupture. Beginning within 3 weeks after surgery, a progressive negative-work exercise program was initiated using an eccentric ergometer. The patient completed 31 training sessions of 5 to 30 minutes in duration over a 12-week period following the ACL-R and 33 training sessions of the same frequency and duration following the ACL revision.Following ACL-R, quadriceps volume increased 28% (involved lower extremity) and 14% (uninvolved lower extremity) during the 12-week training program. Following revision, quadriceps volume returned to similar levels at the same postoperative period as those achieved after the initial surgery (2% less on the involved side and 2% greater on the uninvolved side). Quadriceps strength, 15 weeks after ACL-R, exceeded preoperative measures by an average of 20% (involved) and 14% (uninvolved). Quadriceps strength after ACL revision exceeded all previous measures.This case report suggests that if gradually and progressively applied, negative work via eccentric ergometry can be both safe and efficacious early after ACL-R. Eccentric exercise may mitigate the prevalent muscle size and strength deficits commonly observed after ACL-R. The results of this case suggest a need for continued research with early negative work interventions following ACL-R.

13 Abstract. 14 Background: The natural progression of balance decline in individuals with Parkinson disease (PD) is not well understood. 15 Objectives: We aimed to: 1) compare the utility of three standardized clinical measures for detecting balance decline over 1-year, 2) identify components of balance susceptible to decline, and 3) identify factors useful for predicting future balance decline. 16 17 Methods: Eighty people with PD (59% male; mean age 68.2 ± 9.3; Hoehn & Yahr range I-IV) completed Balance Evaluation Systems Test (BESTest), Mini-BESTest, and Berg Balance Scale (BBS) assessments. Baseline predictor variables included the MDS-UPDRS III sub-score, presence of freezing, 6-month fall history, age, gender, and physical activity. Balance and MDS-UPDRS III assessments were repeated at 6 (n = 51) and 12 months (n = 44). 18 19 20 21 Results: BESTest and Mini-BESTest score declined over 6 and 12 months (P 0.01). MDS-UPDRS III score was unchanged over 6 months (P > 0.01), but declined over 12 months (P < 0.01). Change in BESTest score over 6 months was related to baseline MDS-UPDRS III, H&Y, freezing, and fall history (P < 0.05). Change in BESTest score over 12 months was related to baseline MDS-UPDRS III and freezing (P < 0.05). Change in Mini-BESTest over 12 months was related to baseline MDS-UPDRS III and age (P < 0.05). 22 23 24 25 26 27 Conclusions: The BESTest and Mini-BESTest were responsive to balance decline in individuals with PD and helped to identify decline in underlying balance components. Disease severity and freezing most consistently predicted balance decline in persons with PD. 28 29 30

Researchers have suggested that sensory cues can improve gait initiation in persons with Parkinson's disease (PD); however, there is little research that documents the effects of sensory cues on gait initiation. The purpose of this study was to examine the effects of auditory and cutaneous sensory cues on maximal speed gait initiation in person's with PD and healthy elderly. Seven persons with PD of moderate severity (mean age=69 years) and seven age, gender, and height matched healthy elders participated. Temporal, kinematic and center of pressure (COP) data were recorded as participants performed eight trials within four randomly ordered conditions (no cue (NC), a single auditory cue (SA), repetitive auditory cues (RA), and repetitive cutaneous cues (RC)). In each condition, participants were instructed to perform each gait initiation trial at their maximal speed. In all conditions, person's with PD reacted more slowly and moved less far than did the matched elders. Relative to conditions with NCs, sensory cueing resulted in decreased double limb support (DLS), and increased COP displacement and velocity in both groups. However, in both groups, displacements and velocities of the swing limb and sacrum during the sensory-cued conditions were less than those during the NC condition. These results suggest that when movement speed is a primary goal, sensory cues may interfere with swing limb and body movement outcomes during the gait initiation task in both person's with PD and healthy elders.

OBJECTIVES: Intramuscular adipose tissue (IMAT) is recognized as a negative predictor of both muscle and mobility function in older adults, however the mechanism by which IMAT may negatively influence muscle and mobility function is currently unknown. The release of pro-inflammatory cytokines from IMAT provides a potential reason for these negative associations. To explore this hypothesis we compared IMAT and muscular inflammation in age-and BMI-matched older non-obese frail and non-frail adults. We also sought to examine the relationship between IMAT and inflammation, and muscle and mobility function in this group of older adults. DESIGN: A case-control sampling was used for this study. Age-and BMI-matched non-obese frail and non-frail individuals (

Purpose: The aim of this study was to investigate both the relative and absolute reliability of various dual-task walking tests in people with chronic stroke. Methods: Fifty-one community-dwelling people with chronic stroke participated in this study (mean (SD) age = 62.5 (7.8) years; mean (SD) time since stroke onset = 101.6 (50.8) months). Participants were instructed to perform 3 walking tasks without a concurrent secondary task (i.e., single-task conditions)

Decreased reactive postural responses in elderly adults may place them at increased risk for falls and related injuries. The first step in addressing the high rate of falls in the elderly population is to determine a baseline for postural response in healthy young and healthy elderly individuals. To determine these age-related differences in reactive postural responses during recovery from posterior and anterior perturbations, we used the tether-release method in conjunction with a motion analysis system to evaluate overall movement latencies, overall movement amplitude and velocity, and joint-specific amplitude and velocity in healthy young (n = 10, mean age=25 ± 5) and healthy elderly participants (n = 10, mean age = 67 ± 6). During posterior perturbations, healthy elderly participants had increased recovery time (P = 0.01) and ratio of center of mass to step length (P = 0.013) when compared with young participants. Elderly participants also had decreased step length (P = 0.006), peak COM velocity (P = 0.01), peak knee flexion angle (P = 0.002), and decreased hip (P = 0.005) and knee (P = 0.0005) average angular velocity when compared with young participants. We conclude that these movement deficiencies at the hip and knee limited the length of the recovery step. With this restricted step, elderly participants could not achieve adequate mechanical advantage to counteract the displacement of their COM using a single step. During anterior perturbations, elderly participants did not exhibit any significant differences compared to young participants in overall movement variables. This understanding of postural responses in healthy individuals is clinically relevant to the development of rehabilitation programs for individuals at high fall risk.

Postural instability appears to be a dopamine resistance motor deficit in persons with Parkinson disease (PD); however, little is known about the effects of dopamine replacement on the relative biomechanical contributions of individual lower extremity joints during postural control tasks. To gain insight, we examined persons with PD using both clinical and laboratory measures. For a clinical measure of motor severity we utilized the Unified Parkinson Disease Rating Scale motor subsection during both OFF and ON medication conditions. For the laboratory measure we utilized data gathered during a rapid lower extremity force production task. Kinematic and kinetic variables at the hip, knee, and ankle were gathered during a counter movement jump during both OFF and ON medication conditions. Sixteen persons with PD with a median Hoehn and Yahr severity of 2.5 completed the study. Medication resulted in significant improvements of angular displacement for the hip, knee, and ankle. Furthermore, significant improvements were revealed only at the hip for peak net moments and average angular velocity compared to the OFF medication condition. These results suggest that dopamine replacement medication result in decreased clinical motor disease severity and have a greater influence on kinetics and kinematics proximally. This proximally focused improvement may be due to active recruitment of muscle force and reductions in passive restraint during lower extremity rapid force production.

BackgroundExercise is known to reduce disability and improve quality of life in people with Parkinson disease (PD). Although barriers to exercise have been studied in older adults, barriers in people with chronic progressive neurological diseases, such as PD, are not well defined.ObjectiveThe purpose of this study was to identify perceived barriers to exercise in people with PD.DesignThe study had a cross-sectional design.MethodsPeople who had PD, dwelled in the community, and were at stage 2.4 on the Hoehn and Yahr scale participated in this cross-sectional study (N=260; mean age=67.7 years). Participants were divided into an exercise group (n=164) and a nonexercise group (n=96). Participants self-administered the barriers subscale of the Physical Fitness and Exercise Activity Levels of Older Adults Scale, endorsing or denying specific barriers to exercise participation. Multivariate logistic regression analysis was used to examine the contribution of each barrier to exercise behavior, and odds ratios were reported.ResultsThree barriers were retained in the multivariate regression model. The nonexercise group had significantly greater odds of endorsing low outcome expectation (ie, the participants did not expect to derive benefit from exercise) (odds ratio [OR]=3.93, 95% confidence interval [CI]=2.08–7.42), lack of time (OR=3.36, 95% CI=1.55–7.29), and fear of falling (OR=2.35, 95% CI=1.17–4.71) than the exercise group.LimitationsThe cross-sectional nature of this study limited the ability to make causal inferences.ConclusionsLow outcome expectation from exercise, lack of time to exercise, and fear of falling appear to be important perceived barriers to engaging in exercise in people who have PD, are ambulatory, and dwell in the community. These may be important issues for physical therapists to target in people who have PD and do not exercise regularly. The efficacy of intervention strategies to facilitate exercise adherence in people with PD requires further investigation.

Gait difficulties and falls are commonly reported in people with Parkinson disease (PD). Reduction in gait speed is a major characteristic of Parkinsonian gait, yet little is known about its underlying determinants, its ability to reflect an internal reservation about walking, or its relationship to falls. To study these issues, we selected age, disease severity, and nonmotor factors (i.e., depression, quality of life, balance confidence, and exercise beliefs and attitudes) to predict self-selected (SELF), fast-as-possible (FAST), and the difference (DIFF) between these walking speeds in 78 individuals with PD. We also examined gender differences in gait speeds and evaluated how gait speeds were related to a retrospective fall report. Age, disease severity, and balance confidence were strong predictors of SELF, FAST, and, to a lesser extent, DIFF. All three parameters were strongly associated with falling. DIFF was significantly greater in men compared to women and was significantly associated with male but not female fallers. The results supported the clinical utility of using a suite of gait speed parameters to provide insight into the gait difficulties and differentiating between fallers in people with PD.

Purpose. Persons with Parkinson disease (PD) demonstrate deficits in motor learning as well as bidirectional interference (the performance of one task concurrently interferes with the performance of another task) during dual-task performance. Few studies have examined the practice dosages necessary for behavioral change in rehabilitation relevant tasks. Therefore, to compare the effects of age and PD on motor learning during dual-task performance, this pilot study examined persons with PD as well as neurologically healthy participants during concurrent performance of postural and speaking tasks.Methods. Seven persons with PD and 7 healthy age-matched and 10 healthy young control subjects were tested in a motion capture facility. Task performances were performed concurrently and recorded during 3 time periods (acquisition (beginning and ending), 48-hour retention, and 1-week retention). Postural control and speech articulatory acoustic variables were measured.Results. Healthy young participants consistently performed better than other groups on all measured postural and speech variables. Healthy young participants showed decreased variability at retention, while persons with PD and healthy age-matched controls were unable to consistently improve their performance as a result of practice. No changes were noted in the speech variables.Conclusion. The lack of consistent changes in motor performance in any of the tasks, except in the healthy young group, suggests a decreased efficiency of motor learning in the age-matched and PD groups and argues for increased practice dosages during balance training.

Parkinson's disease (PD) is the second most common neurodegenerative disorder, and increasing age is a major risk factor for development of PD. As such, PD is expected to become increasingly prevalent in coming years as the aged population grows in number. PD is typically treated with pharmacological and sometimes surgical approaches, but these treatments do not adequately address many aspects of the disease. As such, rehabilitation may play a key role in the management of PD. The nine articles in this special issue illustrate the broad spectrum of important rehabilitation issues for people with PD. M. H. Nilsson et al. report relationships between health and housing in very old individuals with PD, examining the impact of environmental barriers and accessibility problems on daily life. A. Letanneux et al. focus on the psychosocial impact of speech impairment in PD, presenting a French version of the Dysarthria Impact Profile. K. B. Foreman et al. also address speech issues, examining the effects of concurrent performance of a speech task and a postural control task in individuals with PD. Postural control is also addressed by G. Vervoort et al., who present evidence of differences in specific aspects of postural control in people with PD who experience freezing of gait compared to those with PD who have no history of freezing of gait. S. T. Nemanich et al. also focus on gait in PD, examining utility of walking speeds for identifying fallers and determining predictors of preferred and fast pace walking speeds. A. Williams et al. examine the relationships between gait and upper extremity movements in PD, studying the effects of amplitude and cadence manipulations. B. K. Randhawa et al. also examine upper extremity performance as assessed by handwriting, demonstrating the acute changes in handwriting following a single intervention session using transcranial magnetic stimulation. L. A. King et al. examine two different exercise interventions, focusing on which outcome measures were most effective for measuring change following agility boot camp or treadmill training. Finally, G. Frazzitta et al. report the effects of a four-week multidisciplinary inpatient rehabilitation program on gait and balance function after completion of the intervention and one year later. The broad scope of work in this special issue is reflective of the far-reaching impact that rehabilitation may have on many aspects of PD, from the individual to the environmental level. Last but not least, the presented work will provide a multilevel understanding of PD motor problems which will feed into the clinical care and optimal rehabilitation for patients with this complex disease. Gammon M. Earhart Leland E. Dibble Terry Ellis Alice Nieuwboer