Ya-Yun Lee

Downhill Walking Training in Individuals with Parkinson's Disease: A Randomized Controlled Trial

Yang YR, Lee YY, Cheng SJ, Wang RY: Downhill walking training in individuals with Parkinsons disease. Objective:The purpose of this study was to examine the effects of downhill walking training on gait and thoracic kyphosis in patients with Parkinsons disease. Design:Thirty-three patients with Parkinsons disease were randomized into an experimental group (n = 16) or a control group (n = 17). Subjects in the experimental group underwent 4-wks of downhill walking training, whereas subjects in the control group received conventional therapy for 4 wks. Gait parameters, thoracic kyphosis, and muscle strength of knee were measured at pretraining, posttraining, and at 1-mo follow-up. Results:There were significant interaction effects between group and time of evaluation on gait parameters and thoracic kyphotic curve. There was also a significant group effect for muscle strength of knee extensors. Conclusions:Our results suggest that downhill walking training is beneficial for improving gait performance in patients with Parkinsons disease and may contribute to maintenance of thoracic posture in these subjects.

Method for Assessing Brain Changes Associated With Gluteus Maximus Activation

STUDY DESIGN Reliability study. OBJECTIVES To determine the feasibility and reliability of using transcranial magnetic stimulation (TMS) to assess corticomotor excitability (CE) of the gluteus maximus. BACKGROUND Sport-specific skill training targeting greater utilization of the gluteus maximus has been proposed as a method to reduce the incidence of noncontact knee injuries. The use of TMS to assess changes in CE may help to determine training-induced central mechanisms associated with gluteus maximus activation. METHODS Within- and between-day reliability was measured in 10 healthy adults. The CE was measured by stimulating the gluteus maximus ìhotspotî at 120% and 150% of motor threshold, while subjects performed a double-leg bridge. An intraclass correlation coefficient (model 2,1), standard error of measurement, and minimal detectable change were calculated to determine the within- and between-day reliability for the following TMS variables: peak-to-peak motor-evoked potential (MEP) amplitudes, cortical silent period, and MEP latency. RESULTS It is feasible to measure the CE of the gluteus maximus with TMS. The intraclass correlation coefficients for all TMS outcome measures ranged from 0.73 to 0.97. The ranges of minimal detectable change, with respect to mean values for each TMS variable, were larger for MEP amplitude (304.7-585.4 µV) compared to those for cortical silent period duration (25.3-40.8 milliseconds) and MEP latency (1.1-2.1 milliseconds). CONCLUSION The present study demonstrated a feasible method for using TMS to measure CE of the gluteus maximus. Small minimal detectable change values for the cortical silent period and MEP latency provide a reference for future studies.

Evidence of altered corticomotor excitability following targeted activation of gluteus maximus training in healthy individuals.

It has been proposed that strengthening and skill training of gluteus maximus (GM) may be beneficial in treating various knee injuries. Given the redundancy of the hip musculature and the small representational area of GM in the primary motor cortex (M1), learning to activate this muscle before prescribing strength exercises and modifying movement strategy would appear to be important. This study aimed to determine whether a short-term activation training program targeting the GM results in neuroplastic changes in M1. Using transcranial magnetic stimulation, motor evoked potentials (MEPs) were obtained in 12 healthy individuals at different stimulation intensities while they performed a double-leg bridge. Participants then completed a home exercise program for ∼1 h/day for 6 days that consisted of a single exercise designed to selectively target the GM. Baseline and post-training input–output curves (IOCs) were generated by graphing average MEP amplitudes and cortical silent period durations against corresponding stimulation intensities. Following the GM activation training, the linear slope of both the MEP IOC and cortical silent period IOC increased significantly. Short-term GM activation training resulted in a significant increase in corticomotor excitability as well as changes in inhibitory processes of the GM. We propose that the observed corticomotor plasticity will enable better utilization of the GM in the more advanced stages of a rehabilitation/training program.

Proximal Fugl-Meyer Assessment Scores Predict Clinically Important Upper Limb Improvement After 3 Stroke Rehabilitative Interventions

OBJECTIVE To identify the baseline motor characteristics of the patients who responded to 3 prominent intervention programs. DESIGN Observational cohort study. SETTING Outpatient rehabilitation clinics. PARTICIPANTS Individuals with chronic stroke (N=174). INTERVENTIONS Participants received 30 hours of constraint-induced movement therapy (CIMT), robot-assisted therapy, or mirror therapy (MT). MAIN OUTCOME MEASURES The primary outcome measure was the change score of the Upper Extremity Fugl-Meyer Assessment (UE-FMA). The potential predicting variables were baseline proximal, distal, and total UE-FMA and Action Research Arm Test scores. We combined polynomial regression analyses and the minimal clinically important difference to stratify the patients as responders and nonresponders for each intervention approach. RESULTS Baseline proximal UE-FMA scores significantly predicted clinically important improvement on the primary outcome measure after all 3 interventions. Participants with baseline proximal UE-FMA scores of approximately <30 benefited significantly from CIMT and robot-assisted therapy, whereas participants with scores between 21 and 35 demonstrated significant improvement after MT. Baseline distal and total UE-FMA and Action Research Arm Test scores could also predict upper limb improvement after CIMT and MT, but not after robot-assisted therapy. CONCLUSIONS This study could inform clinicians about the selection of suitable rehabilitation approaches to help patients achieve clinically meaningful improvement in upper extremity function.

The Effect of Velocity of Joint Mobilization on Corticospinal Excitability in Individuals With a History of Ankle Sprain

Study Design Controlled laboratory study. Background Joint mobilization and manipulation decrease pain and improve patient function. Yet, the processes underlying these changes are not well understood. Measures of corticospinal excitability provide insight into potential mechanisms mediated by the central nervous system. Objectives To investigate the differential effects of joint mobilization and manipulation at the talocrural joint on corticospinal excitability in individuals with resolved symptoms following ankle sprain. Methods Twenty-seven participants with a history of ankle sprain were randomly assigned to the control, joint mobilization, or thrust manipulation group. The motor-evoked potential (MEP) and cortical silent period (CSP) of the tibialis anterior and gastrocnemius were obtained with transcranial magnetic stimulation at rest and during active contraction of the tibialis anterior. The slopes of MEP/CSP input/output curves and the maximal MEP/CSP values were calculated to indicate corticospinal excitability. Behavioral measures, including ankle dorsiflexion and dynamic balance, were evaluated. Results A repeated-measures analysis of variance of the MEP slope showed a significant group-by-time interaction for the tibialis anterior at rest (P = .002) and during active contraction (P = .042). After intervention, the thrust manipulation group had an increase in corticospinal excitability, while the corticospinal excitability decreased in the mobilization group. The thrust manipulation group, but not other groups, also demonstrated a significant increase in the maximal MEP amplitude of the tibialis anterior after intervention. Conclusion The findings suggest that joint manipulation and mobilization have different effects on corticospinal excitability. The increased corticospinal excitability following thrust manipulation may provide a window for physical therapists to optimize muscle recruitment and subsequently movement. The trial was registered at ClinicalTrials.gov (NCT00847769). J Orthop Sports Phys Ther 2016;46(7):562-570. Epub 6 Jun 2016. doi:10.2519/jospt.2016.6602.

Combining Afferent Stimulation and Mirror Therapy for Improving Muscular, Sensorimotor, and Daily Functions After Chronic Stroke: A Randomized, Placebo-Controlled Study.

ObjectiveMirror therapy (MT) combined with mesh glove (MG) afferent stimulation (MT + MG) has been suggested as an effective intervention for motor recovery in patients with stroke. This study aimed to further determine the treatment effects of the MT + MG approach on muscular properties, sensorimotor functions, and daily function. DesignThis was a single-blind, randomized, placebo-controlled study. Forty-eight participants with chronic stroke were recruited from medical centers and were randomly assigned to the MT, MT + MG, and MT with sham MG stimulation (MT + sham) groups. The intervention consisted of 1.5 hrs/day, 5 days/wk for 4 wks. Primary outcomes were the Fugl-Meyer Assessment and muscular properties (muscle tone and stiffness). Secondary outcomes included measures of sensorimotor and daily functions. ResultsCompared with the MT and MT + sham groups, the MT + MG group demonstrated improved muscular properties. The MT + MG and MT + sham groups showed greater improvement in manual dexterity and daily function than the MT group did. No beneficial effects on the Fugl-Meyer Assessment and other sensorimotor outcomes were found for the MT + MG group. ConclusionsAlthough no significant group differences were found in the Fugl-Meyer Assessment, MT + MG induced distinctive effects on muscular properties, manual dexterity, and daily function.

Evolving methods to combine cognitive and physical training for individuals with mild cognitive impairment: study protocol for a randomized controlled study

BackgroundNonpharmacologic interventions, such as cognitive training or physical exercise, are effective in improving cognitive functions for older adults with mild cognitive impairment (MCI). Some researchers have proposed that combining physical exercise with cognitive training may augment the benefits of cognition. However, strong evidence is lacking regarding whether a combined therapy is superior to a single type of training for older adults with MCI. Moreover, which combination approach – combining physical exercise with cognitive training sequentially or simultaneously – is more advantageous for cognitive improvement is not yet clear. This proposed study is designed to clarify these questions.Methods/designThis study is a single-blinded, multicenter, randomized controlled trial. Eighty individuals with MCI will be recruited and randomly assigned to cognitive training (COG), physical exercise training (PE), sequential training (SEQ), and dual-task training (DUAL) groups. The intervention programs will be 90 min/day, 2–3 days/week, for a total of 36 training sessions. The participants in the SEQ group will first perform 45 min of physical exercise followed by 45 min of cognitive training, whereas those in the DUAL group will perform physical exercise and cognitive training simultaneously. Participants will be assessed at baseline, after the intervention, and at 6-month follow-up. The primary cognitive outcome tests will include the Montreal Cognitive Assessment and the color-naming Stroop test. Other outcomes will include assessments that evaluate the cognitive, physical, and daily functions of older adults with MCI.DiscussionThe results of this proposed study will provide important information regarding the feasibility and intervention effects of combining physical exercise and cognitive training for older individuals with MCI.Trial registrationClinicalTrials.gov Identifier: NCT02512627, registered on 20 July 2015.

Context-Dependent Learning in People With Parkinson's Disease

ABSTRACT Context-dependent learning is a phenomenon in which people demonstrate superior performance in the context in which they originally learned a skill but perform less well in a novel context. This study investigated context-dependent learning in people with Parkinsons disease (PD) and age-matched nondisabled adults. All participants practiced 3 finger sequences, each embedded within a unique context (colors and locations on a computer screen). One day after practice, the participants were tested either under the sequence-context associations remained the same as during practice, or the sequence-context associations were changed (SWITCH). Compared with nondisabled adults, people with PD demonstrated significantly greater decrement in performance (especially movement time) under the SWITCH condition, suggesting that individuals with PD are more context dependent than nondisabled adults.

Neural correlates of dual-task practice benefit on motor learning: a repetitive transcranial magnetic stimulation study.

Dual‐task practice has been previously shown to enhance motor learning when both primary and secondary tasks engage similar cognitive processes. In the present study, participants practiced a finger sequence task with the non‐dominant hand under a single‐task condition (i.e. without a probe task) or a dual‐task condition in which a probe choice reaction time (CRT) task was presented during the preparation phase (before movement onset) of the finger task. It was hypothesised that by engaging similar ‘planning’ processes, the dual‐task condition may facilitate the activation of shared ‘planning’ circuitry that includes dorsal premotor cortex (dPM), an important neural substrate for CRT task performance and movement preparation. Repetitive transcranial magnetic stimulation (rTMS; 1 Hz) was applied to the contralateral dPM immediately following practice. Motor learning was assessed by a retention test conducted ~ 24 h after practice. Consistent with our previous results, the dual‐task condition enhanced learning compared with the single‐task condition. rTMS applied to dPM attenuated the dual‐task practice benefit on motor learning. In contrast, rTMS to M1 did not attenuate the dual‐task practice benefit, suggesting the rTMS effect was specific to dPM. Our findings suggest a unique role of dPM in mediating the dual‐task practice effect on motor learning.

Role of the dorsolateral prefrontal cortex in context-dependent motor performance.

Context‐dependent motor performance is a phenomenon in which people perform better in the environmental context where they originally practised a task. Some animal and computer simulation studies have suggested that context‐dependent performance may be associated with neural activation of the dorsolateral prefrontal cortex (DLPFC). This study aimed to determine the role of the DLPFC in context‐dependent motor performance by perturbing the neural processing of the DLPFC with repetitive transcranial magnetic stimulation (rTMS) in healthy adults. Thirty healthy adults were recruited into the Control, rTMS DLPFC and rTMS Vertex groups. The participants practised three finger sequences associated with a specific incidental context (a coloured circle and a location on the computer screen). One day following practice, the rTMS groups received 1 Hz rTMS prior to the testing conditions in which the sequence‐context associations remained the same as practice (SAME) or changed (SWITCH). All three groups improved significantly over practice on day 1. The second day testing results showed that the DLPFC group had a significantly lower decrease in motor performance under the SWITCH condition than the Control and Vertex groups. This finding suggests a specific role of the DLPFC in context‐dependent motor performance.