Association between the Effects of Positive Social-Comparative Feedback and Learners' Competitiveness.

This study examined the effects of positive social-comparative feedback on learners' intrinsic motivation on a motor learning task, as well as its association with learners' competitiveness. The participants, who performed a balance task in a positive social-comparative feedback and a control group, were assessed for performance outcome, perceived competence, and competitiveness. The positive social-comparative feedback group demonstrated more effective balance performance than the control group on the retention test. In addition, the participants in the positive social-comparative feedback group reported significantly higher perceived competence than the participants in the control group after practice. Further, a subscale of learners' competitiveness-instrumental competitiveness-predicted the performance on a retention test in the positive social-comparative feedback group, but not in the control group. Our results suggest that positive social-comparative feedback is not beneficial to all learners, and may even be less effective for learners with lower competitiveness.

Sex Differences in Physical Activity in People After Stroke: A Cross-sectional Study.

OBJECTIVE: Adequate physical activity after stroke is critical for cardiovascular health. Although sex is a potential factor associated with post-stroke physical activity, its mechanism remains unclear. This study aimed to examine sex differences in human physical activity following stroke. METHOD: A cross-sectional study with 62 participants (men: 42, women: 20) was conducted. Physical activity was measured for three consecutive days using a step activity monitor. The walking durations per day in light physical activity, moderate-to-vigorous physical activity, and total physical activity were calculated. Sex differences in walking duration were compared using Welch's t-tests or Mann-Whitney U tests. RESULTS: Women had a significantly greater walking duration in light physical activity and in total than did the men. In contrast, no significant differences were found in moderate-to-vigorous physical activity. CONCLUSION: This study reported sex differences in the walking duration after stroke. Moreover, it found that women spent more time in low intensity physical activity than men. Our results will be useful for planning interventions to increase physical activity and decrease sedentary behavior after stroke.

A questionnaire survey of difficulties in clinical practice perceived by physical therapy students.

[Purpose] We aimed to investigate the difficulties perceived by physical therapy students during clinical practice, and to identify the associated factors based on the results of our previous interview survey. We collected opinions from these students through a questionnaire survey. Furthermore, we analyzed the relationships between the difficulties perceived by physical therapy students during clinical practice and the students' level of achievement at the end of their clinical practice. [Participants and Methods] The study included 176 students, who had completed comprehensive clinical practice during their fourth year, to rate the difficulties perceived by them on an 11-point scale from 0 to 10. [Results] There were 127 responses. Through exploratory factor analysis, 43 items representing 5 factors were selected: Factor 1, difficulties related to communication of behavioral improvement/relationship building; Factor 2, difficulty obtaining supportive guidance/having appropriate learning environments coordinated; Factor 3, difficulty organizing/expressing clinical reasoning for physical therapy; Factor 4, difficulty learning in the clinical practice environment; and Factor 5, difficulty managing patients/adapting to the environment. [Conclusion] Regardless of the level of achievement at the end of clinical practice, the students strongly perceived "Factor 2: difficulty obtaining supportive guidance/having appropriate learning environments coordinated". The results identified the factors associated with the difficulties perceived by physical therapy students during clinical practice, thereby providing a basis for resolving such difficulties.

How does physical guidance affect motor learning and learner's workload?

[Purpose] Physical guidance is routinely used in clinical practices such as rehabilitation to facilitate motor learning. Physical guidance would facilitate motor learning and reduce the workload; however, this relationship is unknown. Thus, we aimed to investigate this relationship using a physical guidance device. [Participants and Methods] Twenty-seven healthy young adults were randomly assigned to three groups and underwent varying practice conditions. The participants used a physical guidance device during practice for 2 days, did not use the device during practice for 2 days, or used the device on the first but not the second practice day. Motor learning was assessed by measuring the instability generated by the participants while maintaining a standing position on the Biodex Balance System. Psychological status was evaluated by analyzing the participants' responses to the National Aeronautics and Space Administration-Task Load Index. [Results] Improved performance was noted in all participants; however, those who used a physical guidance device during practice for 2 days exhibited poor motor learning compared with those assigned to the other two conditions. Frustration was significantly lower in participants who used a physical guidance device during practice than those who did not. [Conclusion] The use of physical guidance during practice can reduce participant frustration, but excessive physical guidance during practice reduces learning efficiency.

Relationship between correcting error and smoothness of movement in the process of motor learning.

[Purpose] Improvement in the smoothness of movement is a motor learning outcome. This study sought to clarify the relationship between motor skills and smoothness of movement in motor learning. [Participants and Methods] We subjected 12 healthy adults to a task in which they had to learn the sensation of a load while standing up and sitting down. We attached triaxial accelerometers to the seventh cervical spine and the third lumbar spinous process of the participants prior to measurement. We took the measurements over two successive days and used absolute error and variable error as indicators of motor learning outcomes. In addition, we used entropy, calculated from the results of the power spectrum analysis of acceleration changes, as an indicator of the smoothness of the movement. [Results] In the test sessions, absolute and variable errors showed a significant reduction. Entropy also showed a similarly significant decrease, although the change in errors and entropy showed different transitions. [Conclusion] Qualitative indicators of motor learning captured an aspect of motor learning that one cannot capture by quantitative indicators. In the future, qualitative indicators will be necessary to judge the outcomes of motor learning.

Extrinsic feedback from a feedback device promotes the learning of range of motion measurements.

[Purpose] Although it is widely recognized that feedback is important for skill acquisition or improvement, feedback is not completely utilized in physical therapy education. Therefore, we aimed to verify the effect of extrinsic feedback from a feedback device on proficiency in range of motion measurements by a universal goniometer. [Participants and Methods] The participants included 22 physical therapy students who were randomly assigned to feedback (n=11) and non-feedback groups (n=11). The passive right knee flexion range of motion was set as the measurement task. The experiment consisted of a pretest phase, practice trials, and a posttest phase. In the pretest phase, all participants conducted three measurements without extrinsic feedback. Extrinsic feedback related to measurement error from a device was given only to the feedback group. The posttest was conducted 24 hours after the practice trials with the same content as that in the pretest. [Results] The improvement rate from pretest to posttest was greater in the feedback group than in the non-feedback group. The results indicated that the measurement error decreases with extrinsic measurement error-related feedback during practice. [Conclusion] The utilization of extrinsic feedback from a feedback device is effective for enhancing range of motion measurement skills.

Walking activity in community-dwelling stroke survivors within 1 month after discharge from a rehabilitation setting.

Objective: To characterize the pattern of activity accumulation in stroke survivors.Method: Nineteen stroke patients and 19 age-sex-matched healthy adults participated. Step counts were measured using a step activity monitor for 3 d. The steps per day, bouts per day, walking time per day, average steps per bout, and average walking time per bout were calculated in each walking-distance category (short, medium, and long-distance bout) and in total.Results: The total steps per day were 8446 and 11,749 steps in stroke survivors and control participants, respectively. The total steps per day and the total bouts per day for the stroke group were both significantly lower compared with the control group. Significant group differences were found in only the medium-distance range. No significant differences were found in average steps per bout.Conclusion: Fewer number of bouts is a characteristic pattern of walking activity in stroke survivors. In particular, a low number of medium-distance bouts in stroke survivors results in a low number of daily steps when compared with healthy adults. To facilitate physical activity in stroke survivors, not only the total number of bouts per day but the number of bouts of varying lengths must be considered. Implications for rehabilitationFewer number of bouts is a characteristic pattern of walking activity in stroke survivors.Low number of bouts, especially medium-distance bouts, in stroke survivors, results in low number of daily steps when compared with healthy adults.The number of long-distance bouts is important for increasing total daily steps after stroke with mild disability.To facilitate physical activity in stroke survivors, not only the total number of bouts per day but the number of bouts of varying lengths must be considered.

Differences in skill level influence the effects of visual feedback on motor learning.

[Purpose] No previous studies have confirmed whether the effects of visual feedback on motor learning vary according to learner skill level for a learning task. The purpose of this study was to clarify whether differences in skill influence the effects of visual feedback on motor learning. [Participants and Methods] Sixty-four participants were assigned to one of four different feedback groups (concurrent-100%, concurrent-50%, terminal-100%, or terminal-50%). The learning task was to adjust the load amount continuously to the left lower limb in accordance with sound stimulation at intervals of 1 Hz. The four groups performed a pretest, practice sessions, and a retention test 24 hours after practice. After completing these measurements, the participants were classified as either high- or low-skilled based on the results of the pretest. [Results] Only the groups of low-skilled participants who used concurrent feedback showed lower root mean square errors in the retention test compared to in the pretest. [Conclusion] Differences in skill level for the same task influenced the effects of visual feedback on motor learning. Furthermore, concurrent visual feedback can help improve motor learning in low-skilled learners for the same task.

Neural mechanism of selective finger movement independent of synergistic movement.

Muscle synergy is important for simplifying functional movement, which constitutes spatiotemporal patterns of activity across muscles. To execute selective finger movements that are independent of synergistic movement patterns, we hypothesized that inhibitory neural activity is necessary to suppress enslaved finger movement caused by synergist muscles. To test this hypothesis, we focused on a pair of synergist muscles used in the hand opening movement, namely the index finger abductor and little finger abductor (abductor digiti minimi; ADM), and examined whether inhibitory neural activity in ADM occurs during selective index finger abduction/adduction movements and/or its imagery using transcranial magnetic stimulation and F-wave analysis. During the index finger adduction movement, background EMG activity, F-wave persistence, and motor evoked potential (MEP) amplitude in ADM were elevated. However, during the index finger abduction movement, ADM MEP amplitude remained unchanged despite increased background EMG activity and F-wave persistence. These results suggest that increased spinal excitability in ADM is counterbalanced by cortical-mediated inhibition only during selective index finger abduction movement. This assumption was further supported by the results of motor imagery experiments. Although F-wave persistence in ADM increased only during motor imagery of index finger abduction, ADM MEP amplitude during motor imagery of index finger abduction was significantly lower than that during adduction. Overall, our findings indicate that cortical-mediated inhibition contributes to the execution of selective finger movements that are independent of synergistic hand movement patterns.

Dissociation between cortical and spinal excitability of the antagonist muscle during combined motor imagery and action observation.

Inhibitory neural control of antagonist muscle is one of the fundamental neural mechanism of coordinated human limb movement. Previous studies have revealed that motor execution (ME) and motor imagery (MI) share many common neural substrates; however, whether inhibitory neural activity occurs during MI remains unknown. In addition, recent studies have demonstrated that a combined MI and action observation (MI + AO) produces strong neurophysiological changes compared with MI or AO alone. Therefore, we investigated inhibitory changes in cortical and spinal excitability of the antagonist muscle during MI + AO and ME. Single-pulse transcranial magnetic stimulation (TMS) experiments revealed that corticospinal excitability of the antagonist muscle was decreased during MI + AO. Conversely, F-wave experiments showed that F-wave persistence of the antagonist muscle increased. Paired-pulse TMS experiment also demonstrated that short-interval intracortical inhibition (SICI) did not contribute to this inhibition. Therefore, cortical mediated inhibition, except for SICI, may be related to this inhibition. Conversely, such clear inhibition of the antagonist muscle was not observed during ME, presumably owing to the effects of muscle contraction to decelerate the movements and/or sensory input accompanying the joint movements. These findings provide important insights into the neurophysiological differences between MI + AO and ME.

The effects of feedback timing and frequency on the acquisition of cardiopulmonary resuscitation skills of health sciences undergraduate students: A 2 x 2 factorial quasi randomized study.

BACKGROUND: High-quality training is required to improve the cardiopulmonary resuscitation (CPR) skills. Although it has been reported that the use of a feedback device is effective, the effects of feedback timing and frequency on CPR training have not been investigated. The aim of this study was to clarify the influence of feedback frequency and timing on the acquisition of CPR skills. METHODS: Sixty-eight undergraduates were first divided into female (n = 32) and male (n = 36) groups, and randomly assigned to one of four groups for each sex: concurrent-100%, concurrent-50%, terminal-100%, and terminal-50% feedback groups. The randomization was performed using a lottery method. This study consisted of a pre-test, practice sessions, a post-test, and a follow-up test. In the practice sessions, the participants performed six 2-minute CPR sessions in accordance with the condition assigned using mannequins and feedback devices. The post-test was conducted 24 hours after the completion of the practice sessions and the follow-up test was conducted 3 months after the completion of the practice sessions. The primary outcome of the study was the overall score at the follow-up test. RESULTS: The results of the overall score at the follow-up test for each group were 88.2 ± 9.6% for concurrent-100%, 92.2 ± 6.4% for concurrent-50%, 82.6 ± 16.4% for terminal-100%, and 85.2 ± 16.9% for terminal-50%. We did not find any statistically significant difference for the overall score at the follow-up test among the four groups (p = 0.173). The ANOVA for the test sessions revealed that there were no significant main effects of feedback timing (p = 0.135) or frequency (p = 0.765), and no significant interaction between timing and frequency (p = 0.997). CONCLUSION: The present study reveals that the use of feedback devices is an important factor for higher quality CPR training, regardless of the timing and frequency with which they are used.

Usefulness of an unstable board balance test to accurately identify community-dwelling elderly individuals with a history of falls.

OBJECTIVE: To determine the usefulness of an un-stable board balance test in identifying a fall history among high-functioning community-dwelling elderly individuals. DESIGN: Case-control study. SUBJECTS: Sixty-one community-dwelling elderly aged ≥ 65 years and having the capacity to walk independently without an assistive device. METHODS: Subjects completed 3 balance performance tests: the Unstable Board Balance Test, Functional Reach Test, and Timed Up and Go. For analysis, subjects were classified as fallers or non-fallers based on the history of falls over the previous year, and performance outcomes were compared between the 2 groups. Subjects classified as fallers were then matched 1:1 with non-fallers (for sex, age, body weight and height), and the optimal cut-off score and area under the receiver operating characteristic curve (AUC) for each test were calculated. RESULTS: Functional reach test and Timed Up and Go did not reliably discriminate between fallers and non-fallers. In contrast, the score on the unstable board balance test was significantly different between the 2 groups (p = 0.040). Among all 3 tests, AUC was largest for the unstable board balance test (0.78), with superior sensitivity (0.67) and specificity (0.87). CONCLUSION: For high-functioning elderly subjects, the unstable board balance test was useful in discriminating between fallers and non-fallers.

Dynamic balance assessment using an unstable board in community-dwelling elderly people.

[Purpose] A new method for measuring dynamic balance was developed. The aim of this study was to describe the use of a novel "unstable board" to evaluate the balance ability of community-dwelling elderly individuals. [Participants and Methods] The following balance outcomes were evaluated in 59 community-dwelling elderly people: anteroposterior and mediolateral stability indexes on the unstable board, Mini-Balance Evaluation Systems Test score, the Functional Reach Test score, Timed Up-and-Go time, and the Figure-8 Walk Test time. [Results] With respect to the relationship between the stability indexes and functional balance scales, the anteroposterior stability index significantly correlated with the anticipatory postural adjustment component (r=-0.422), stability in the gait component (r=-0.274), and total score of the Mini-Balance Evaluation Systems Test (r=-0.316); timed up-and-go time (r=0.320); and figure-8 walk test time (r=0.340). No correlation was found between the mediolateral stability index and the functional balance scale scores. [Conclusion] The anteroposterior stability index correlated with the declines in postural adjustments and performance in the dynamic balance assessments. Therefore, the anteroposterior stability index, evaluated on an unstable board, could provide an efficient tool for predicting changes in dynamic balance capacity, which could not be identified using the most commonly used balance assessment tools.

Distinct roles for U-type proteins in iron-sulfur cluster biosynthesis revealed by genetic analysis of the Bacillus subtilis sufCDSUB operon.

The biosynthesis of iron-sulfur (Fe-S) clusters in Bacillus subtilis is mediated by the SUF-like system composed of the sufCDSUB gene products. This system is unique in that it is a chimeric machinery comprising homologues of E. coli SUF components (SufS, SufB, SufC and SufD) and an ISC component (IscU). B. subtilis SufS cysteine desulfurase transfers persulfide sulfur to SufU (the IscU homologue); however, it has remained controversial whether SufU serves as a scaffold for Fe-S cluster assembly, like IscU, or acts as a sulfur shuttle protein, like E. coli SufE. Here we report that reengineering of the isoprenoid biosynthetic pathway in B. subtilis can offset the indispensability of the sufCDSUB operon, allowing the resultant Δsuf mutants to grow without detectable Fe-S proteins. Heterologous bidirectional complementation studies using B. subtilis and E. coli mutants showed that B. subtilis SufSU is interchangeable with E. coli SufSE but not with IscSU. In addition, functional similarity in SufB, SufC and SufD was observed between B. subtilis and E. coli. Our findings thus indicate that B. subtilis SufU is the protein that transfers sulfur from SufS to SufB, and that the SufBCD complex is the site of Fe-S cluster assembly.

The relationship between physical function in the elderly and judgment error in walking speed.

[Purpose] "Judgment error," defined as a difference between the actual and the imagined performance, is often observed in elderly persons. The aims of this study were to assess subjective judgment errors in elderly persons, and to evaluate the relationship between physical function and judgment error in walking speed. [Subjects and Methods] A total of 106 community-dwelling elderly individuals participated. Subjects observed video footage of a model walking an obstacle course, and were asked to subjectively compare the model's gait speed with their own gait speed. When the subjective comparison differed from the actual difference, it was considered as a judgment error. Physical function was compared between those with and without judgment error. [Results] Significant interaction effects between the actual performance and subjective perception were found for the walking time on the obstacle course and the Activities-specific Balance Confidence Scale score (utilized as an index of self-confidence in own balance ability and a fear of falling). [Conclusion] The results demonstrate that some elderly persons tend to overestimate their balance and ambulation function compared to another person, even though they had low physical function and low self-confidence in terms of balance. These elderly individuals might have a high risk of accidents.

The effect of proficiency level on measurement error of range of motion.

[Purpose] The aims of this study were to evaluate the type and extent of error in the measurement of range of motion and to evaluate the effect of evaluators' proficiency level on measurement error. [Subjects and Methods] The participants were 45 university students, in different years of their physical therapy education, and 21 physical therapists, with up to three years of clinical experience in a general hospital. Range of motion of right knee flexion was measured using a universal goniometer. An electrogoniometer attached to the right knee and hidden from the view of the participants was used as the criterion to evaluate error in measurement using the universal goniometer. The type and magnitude of error were evaluated using the Bland-Altman method. [Results] Measurements with the universal goniometer were not influenced by systematic bias. The extent of random error in measurement decreased as the level of proficiency and clinical experience increased. [Conclusion] Measurements of range of motion obtained using a universal goniometer are influenced by random errors, with the extent of error being a factor of proficiency. Therefore, increasing the amount of practice would be an effective strategy for improving the accuracy of range of motion measurements.

Characteristics of tasks utilized for evaluation of judgment errors in the elderly.

[Purpose] The present study compared assessments utilized to evaluate judgment errors in the elderly. [Subjects and Methods] A total of 94 community-dwelling elderly participants in an examination of physical fitness for health promotion and health guidance in a rural area in Japan were included. Spatially and temporally predictive tasks were used to evaluate judgment errors. Distances measured on the Functional Reach and upward reaching tests were used to assess spatial prediction, and times measured on the Timed Up and Go test and Standardized Walking Obstacle Course were used to assess temporal prediction. Differences between the self-predicted values and actual results were deemed judgment errors. [Results] Significant differences were observed between self-predicted abilities and the patients' performances. Participants underestimated their abilities in spatially predictive tasks and overestimated them in temporally predictive tasks. On comparing the four tasks, there were significant differences in judgment error ratios between them. Statistical analysis indicated a significant difference in the judgment error ratio for the Standardized Walking Obstacle Course correlated with a history of falls. [Conclusion] Judgment errors were identified using both spatially and temporally predictive tasks. A temporally predictive task like the Standardized Walking Obstacle Course might better evaluate judgment errors in the elderly.

Surround inhibition in motor execution and motor imagery.

Surround inhibition (SI) is a neural mechanism to focus neuronal activity and facilitate selective motor execution (ME). The aim of the present study was to investigate whether SI is also generated during motor imagery (MI). Furthermore, we investigated whether the extent of SI during MI depends on the strength of SI during ME and/or vividness of MI. The extent of SI was examined during MI and ME of index finger flexion. Transcranial magnetic stimulation was applied at rest, during initiation of the movement (phasic phase) and during tonic muscle contraction of the index finger flexors. Motor evoked potentials (MEPs) were recorded from a surround muscle, abductor digiti minimi (ADM) and a synergistic muscle, the first dorsal interosseous muscle. The amplitude of ADM MEP was reduced during the phasic phase, which indicates that SI occurred during ME. In seven of 14 subjects, SI was also observed during MI, although this effect was not significant. There was a moderate correlation between the extent of SI during ME and MI. Furthermore, good imagers who experienced vivid MI during the MI task showed stronger SI than poor imagers. These results indicate that common neural substrates involved in SI during ME are at least in part recruited during MI. In clinical situations, the therapeutic use of MI to generate vivid MI may be one of effective tool to develop the strength of SI, which facilitate selective execution of desired movements.

Age effects on the control of dynamic balance during step adjustments under temporal constraints.

This study investigated the age effects on the control of dynamic balance during step adjustments under temporal constraints. Fifteen young adults and 14 older adults avoided a virtual white planar obstacle by lengthening or shortening their steps under free or constrained conditions. In the anterior-posterior direction, older adults demonstrated significantly decreased center of mass velocity at the swing foot contact under temporal constraints. Additionally, the distances between the 'extrapolated center of mass' position and base of support at the swing foot contact were greater in older adults than young adults. In the mediolateral direction, center of mass displacement was significantly increased in older adults compared with young adults. Consequently, older adults showed a significantly increased step width at the swing foot contact in the constraint condition. Overall, these data suggest that older adults demonstrate a conservative strategy to maintain anterior-posterior stability. By contrast, although older adults are able to modulate their step width to maintain mediolateral dynamic balance, age-related changes in mediolateral balance control under temporal constraints may increase the risk of falls in the lateral direction during obstacle negotiation.

Measurement of functional task difficulty during motor learning: What level of difficulty corresponds to the optimal challenge point?

The relationship between task difficulty and learning benefit was examined, as was the measurability of task difficulty. Participants were required to learn a postural control task on an unstable surface at one of four different task difficulty levels. Results from the retention test showed an inverted-U relationship between task difficulty during acquisition and motor learning. The second-highest level of task difficulty was the most effective for motor learning, while learning was delayed at the most and least difficult levels. Additionally, the results indicate that salivary α-amylase and the performance dimension of the National Aeronautics and Space Administration-Task Load Index (NASA-TLX) are useful indices of task difficulty. Our findings suggested that instructors may be able to adjust task difficulty based on salivary α-amylase and the performance dimension of the NASA-TLX to enhance learning.