Learning a partial-weight-bearing skill: effectiveness of two forms of feedback

Baseline GABA+ levels in areas associated with sensorimotor control predict initial and long-term motor learning progress

Synaptic plasticity relies on the balance between excitation and inhibition in the brain. As the primary inhibitory and excitatory neurotransmitters, gamma-aminobutyric acid (GABA) and glutamate (Glu), play critical roles in synaptic plasticity and learning. However, the role of these neurometabolites in motor learning is still unclear. Furthermore, it remains to be investigated which neurometabolite levels from the regions composing the sensorimotor network predict future learning outcome. Here, we studied the role of baseline neurometabolite levels in four task-related brain areas during different stages of motor skill learning under two different feedback (FB) conditions. Fifty-one healthy participants were trained on a bimanual motor task over 5 days while receiving either concurrent augmented visual FB (CA-VFB group, N = 25) or terminal intrinsic visual FB (TA-VFB group, N = 26) of their performance. Additionally, MRS-measured baseline GABA+ (GABA + macromolecules) and Glx (Glu + glutamine) levels were measured in the primary motor cortex (M1), primary somatosensory cortex (S1), dorsolateral prefrontal cortex (DLPFC), and medial temporal cortex (MT/V5). Behaviorally, our results revealed that the CA-VFB group outperformed the TA-VFB group during task performance in the presence of augmented VFB, while the TA-VFB group outperformed the CA-VFB group in the absence of augmented FB. Moreover, baseline M1 GABA+ levels positively predicted and DLPFC GABA+ levels negatively predicted both initial and long-term motor learning progress in the TA-VFB group. In contrast, baseline S1 GABA+ levels positively predicted initial and long-term motor learning progress in the CA-VFB group. Glx levels did not predict learning progress. Together, these findings suggest that baseline GABA+ levels predict motor learning capability, yet depending on the FB training conditions afforded to the participants.

Do Patients Achieve "Full Weight-bearing" Immediately Following Application of Circular Frame Fixation of the Lower Limb?

Introduction

The decision to use circular frame fixation for lower limb trauma, or elective deformity correction, often accompanies the assertion that the patient will be able to fully weight-bear through the limb immediately following surgery.

Materials and methods

About 53 patients underwent retrospective review. Included in the study were current attendees of adult specialist physiotherapy, following circular frame application to the lower leg at our Institution between August 2018 and January 2020. Cases with incomplete data, cases given postoperative status of non-weight-bearing, those with physiotherapy follow-up conducted elsewhere, or cases of polytrauma were excluded from the study.Weight-bearing assessment and rehabilitation supervision were at the discretion of the physiotherapy team. The clinical concept of 'full weight-bearing' is poorly defined, but was documented in the context of displaying a stable gait using elbow crutches and subsequently without walking aids. Comparative data was analysed using an unpaired, two-tailed Welch's t-test.

Results

Mean postoperative time to full weight-bearing using crutches was 28.3 days (0-159) (n = 40).Mean postoperative time to independent full weight-bearing with no walking aids was 230.6 days (35-393), or 7.1 months (0-12) (n= 34).No significant differences were seen between:Frames for open injuries (n= 5) vs closed injuries (n = 17; p > 0.4).Joint-spanning constructs (n= 18) vs non-spanning constructs (n = 21; p > 0.6), orTreatment of intra-articular injuries (n = 14) vs extra-articular injuries (n = 17; p > 0.2).Interpretation of these results should be made with caution due to sample size.

Conclusion

The ability to permit patients to fully weight-bear immediately after surgery is often a distinct advantage of the circular frame over other fixation modalities, for a variety of indications. However, it does not follow that patients are capable of doing so; there is a long dependency on walking aids. This would appear to be the case irrespective of open/closed injuries, intra-/extra-articular injuries, or the use of a spanning construct across the knee or ankle.

How to cite this article

Craig A, Barron E, Sharma H, et al. Do Patients Achieve "Full Weight-bearing" Immediately Following Application of Circular Frame Fixation of the Lower Limb? Strategies Trauma Limb Reconstr 2024;19(1):40-44.

Concurrent Force Feedback on Load Symmetry in Total Knee Arthroplasty Patients

Background and Purpose

Load asymmetry can be present before and after total knee arthroplasty (TKA), which may affect progress during knee rehabilitation in an outpatient sports medicine setting. Current rehabilitation primarily focuses on strength, pain, and range of motion deficits; however, recent evidence suggests the use of movement retraining strategies such as load feedback to address load asymmetry. Therefore, the purpose of this study was to examine how a single session of concurrent force feedback influences load symmetry during the leg-press and body-weight squat exercises in individuals following TKA. Additionally, a secondary purpose was to examine the retention of any changes over the course of a week.

Study design

Case-series study.

Methods

This observational, repeated-measures study design examined the effect of concurrent force feedback training on the mean and standard deviation of load symmetry index during the leg press and squat exercises in 26 patients with TKA in an outpatient sports medicine clinic.The load asymmetry was measured with loadpad sensors placed underneath the each extremity during leg press and squat (baseline), after one training session consisting of concurrent force feedback during these exercises within a single physical therapy session (post feedback), and after seven to ten days of a washout period (post retention). Separate 2 x 3 repeated measures analysis of variance was used to compare the mean and standard deviation of load symmetry across exercise (leg press and squat) and across time (baseline, post feedback and post retention).

Results

There was a time effect for the mean load symmetry index (p=0.027) but not for the standard deviation (p=0.441) during these exercises. The leg press showed a greater mean symmetry index compared to the squat regardless of time (p=0.001).

Conclusions

A reduction in the mean load symmetry index following concurrent feedback training suggests improved use of the surgical limb during both leg press and squat exercises during the same therapy session but the more symmetric loading pattern was not retained one week later. Overall, the leg press showed greater mean asymmetry than the squat. Standard deviation in the load symmetry index did not change across time or by exercise.

Level of Evidence

3©The Author(s).

A Wearable Mixed Reality Platform to Augment Overground Walking: A Feasibility Study

Humans routinely modify their walking speed to adapt to functional goals and physical demands. However, damage to the central nervous system (CNS) often results in abnormal modulation of walking speed and increased risk of falls. There is considerable interest in treatment modalities that can provide safe and salient training opportunities, feedback about walking performance, and that may augment less reliable sensory feedback within the CNS after injury or disease. Fully immersive virtual reality technologies show benefits in boosting training-related gains in walking performance; however, they lack views of the real world that may limit functional carryover. Augmented reality and mixed reality head-mount displays (MR-HMD) provide partially immersive environments to extend the virtual reality benefits of interacting with virtual objects but within an unobstructed view of the real world. Despite this potential advantage, the feasibility of using MR-HMD visual feedback to promote goal-directed changes in overground walking speed remains unclear. Thus, we developed and evaluated a novel mixed reality application using the Microsoft HoloLens MR-HMD that provided real-time walking speed targets and augmented visual feedback during overground walking. We tested the application in a group of adults not living with disability and examined if they could use the targets and visual feedback to walk at 85%, 100%, and 115% of each individual’s self-selected speed. We examined whether individuals were able to meet each target gait speed and explored differences in accuracy across repeated trials and at the different speeds. Additionally, given the importance of task-specificity to therapeutic interventions, we examined if walking speed adjustment strategies were consistent with those observed during usual overground walking, and if walking with the MR-HMD resulted in increased variability in gait parameters. Overall, participants matched their overground walking speed to the target speed of the MR-HMD visual feedback conditions (all p-values > 0.05). The percent inaccuracy was approximately 5% across all speed matching conditions and remained consistent across walking trials after the first overall walking trial. Walking with the MR-HMD did not result in more variability in walking speed, however, we observed more variability in stride length and time when walking with feedback from the MR-HMD compared to walking without feedback. The findings offer support for mixed reality-based visual feedback as a method to provoke goal-specific changes in overground walking behavior. Further studies are necessary to determine the clinical safety and efficacy of this MR-HMD technology to provide extrinsic sensory feedback in combination with traditional treatments in rehabilitation.

Effects of assistive insole feedback training on immediate and multi-day partial weight bearing retention during walking: A pilot study

BACKGROUND

Adherence to partial weight bearing (PWB) plays a crucial role in early rehabilitation and motor control. Dynamic biofeedback insole systems provide a supportive function on immediate PWB adherence, while important long-term retention effects and potential advantages to a conventional static training remain unknown.

RESEARCH QUESTION

Is acoustic insole feedback training effective for the retention of prescribed PWB adherence and is there any advantage relative to static training using a conventional bathroom scale? Methods Twenty-four volunteers were randomized into two groups receiving biofeedback training (N = 12) via a mobile insole system (Loadsol®) or conventional training using a bathroom scale (N = 12). After initial PWB training (20 kg) of one randomized leg, the immediate and one-week retention effects were analysed using mean and maximum load (N) and overload rate (%). Statistical analysis was performed using a two-way repeated measures ANOVA with post-hoc pairwise comparisons (p < 0.05).

RESULTS

A significantly (p < 0.001) improved immediate and long-term PWB adherence was found for the insole feedback group during walking. A significant (p < 0.001) reduction of the overload rate by 86% was found for the insole feedback group when compared to the conventional training group after one week. Significant (p < 0.01) reductions by 51% and 46% was also found for the mean and maximum load in the insole feedback group when compared to the conventional training group.

SIGNIFICANCE

The use of insole feedback systems can serve as a viable tool to become familiar with PWB and to provide optimal retention of specified loads. Therefore, such systems serve as an advantageous training intervention to maintain a prescribed PWB during locomotion.

Role of Post-Trial Visual Feedback on Unintentional Force Drift During Isometric Finger Force Production Tasks

A reduction in fingertip forces during a visually occluded isometric task is called unintentional drift. In this study, unintentional drift was studied for two conditions, with and without "epilogue." We define epilogue as the posttrial visual feedback in which the outcome of the just-concluded trial is shown before the start of the next trial. For this study, 14 healthy participants were recruited and were instructed to produce fingertip forces to match a target line at 15% maximum voluntary contraction. The results showed a significant reduction in unintentional drift in the epilogue condition. This reduction is probably due to the difference in the shift in λ, the threshold of the tonic stretch reflex, the hypothetical control variable that the central controller can set.

A randomized controlled trial comparing the clinical efficacy and cost-effectiveness of eye movement desensitization and reprocessing (EMDR) and integrated EMDR-Dialectical Behavioural Therapy (DBT) in the treatment of patients with post-traumatic stress disorder and comorbid (Sub)clinical borderline personality disorder: study design

BACKGROUND

Comorbidity between Posttraumatic Stress Disorder (PTSD) and Borderline Personality Disorder (BPD) is high. There is growing motivation among clinicians to offer PTSD treatments - such as Eye Movement Desensitization and Reprocessing (EMDR) - to patients with PTSD and comorbid BPD. However, a large subgroup with comorbid BPD does not sufficiently respond to PTSD treatment and is more likely to be excluded or to dropout from treatment. Dialectical Behaviour Therapy (DBT) for BPD is well established and although there is some evidence that DBT combined with DBT Prolonged Exposure (DBT + DBT PE) is twice as effective in reducing PTSD symptoms than DBT alone, the comparative efficacy of integrated PTSD-DBT and PTSD-only treatment has not been investigated yet. The current study will therefore evaluate the comparative clinical efficacy and cost-effectiveness of EMDR-DBT and EMDR-only in patients with PTSD and comorbid (sub)clinical BPD. Moreover, it is not clear yet what treatment works best for which individual patient. The current study will therefore evaluate neurobiological predictors and mediators of the individual response to treatment.

METHOD

A randomized controlled trial comparing the clinical efficacy and cost-effectiveness of integrated EMDR-DBT (n = 63) and EMDR-only (n = 63) in treatment-seeking adult patients with PTSD and comorbid (sub)clinical BPD. In addition, neurobiological predictors and mediators of treatment outcome, such as hair cortisol, FKBP5 and BDNF protein levels and FKBP5 and BDNF methylation status, are measured through hair and blood samples.

DISCUSSION

This is the first study to compare the clinical efficacy and cost-effectiveness of integrated EMDR-DBT and EMDR-only in patients with PTSD and comorbid (sub)clinical BPD, while simultaneously identifying individual predictors and mediators of treatment response. Results will reveal which treatment works best for which individual patient, thereby guiding individual treatment choices and personalizing psychiatry.

TRIAL REGISTRATION

Clinical Trials, NCT03833453 . Retrospectively registered, 15 March 2019.

Comparison of Feedback Approaches to Improve Training in Partial Weight-Bearing

Assistive devices, including canes or crutches, are used in partial weight-bearing (PWB) to offload weight from limbs weakened by disease or injury, promote recovery, and prevent reinjury. While weight must be offloaded accurately to target loads prescribed by healthcare providers for maximum benefit, current training methods result in poor adherence. It is, however, currently unknown how best to provide feedback during training so that users can build an accurate internal model for PWB. In this work, we investigate seven feedback schemes using an instrumented cane, which vary the modality, timing, and the level of detail provided. We find that auditory schemes and a retrospective visual scheme outperform current clinical practices for PWB training. These findings provide results that can be applied directly to improve current clinical practices and provide valuable new insight into the design of feedback for training internal models in force-based motor control tasks. Clinically, this work presents a simple modification to clinical PWB training practices that can improve compliance by up to 75%, positively influencing rehabilitation outcomes and reducing the risk of complications.

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.

Scheduling Concurrent Visual Feedback in Learning a Continuous Balance Task

This investigation held concurrent visual feedback frequency at 50% in the acquisition phase and manipulated three different feedback schedules while comparing those to a 0% feedback frequency. In an assessment of dynamic postural stability, young, healthy adults performed 20 acquisition trials and four retention trials 48-hr later on a circular platform that moved in the anterior/posterior and medial/lateral axes simultaneously. Three concurrent feedback schedules were manipulated: a fade schedule consisting of high relative frequency of concurrent feedback early in the acquisition phase which was systematically reduced throughout acquisition (e.g., 100%, 75%, 50%, 25%, 0%), a constant schedule consisting of a uniform scheduling of concurrent feedback on every other acquisition trial, and a reverse fade group consisting of a schedule exactly opposite to that of the fade group. A no concurrent feedback group was also utilized to determine if feedback was necessary to learn the balance task. Acquisition and retention results revealed the concurrent groups performed with significantly greater accuracy and stability than the no concurrent feedback group. There were no significant differences between the three concurrent feedback schedules. Results indicate that manipulating concurrent feedback scheduling did not produce similar results to those investigations manipulating knowledge of results scheduling.

[A new continuous gait analysis system for ankle fracture aftercare]

BACKGROUND

Correct aftercare following lower extremity fractures remains a controversial issue. Reliable, clinically applicable weight-bearing recommendations have not yet been defined. The aim of the current study was to establish a new gait analysis insole during physical therapy aftercare of ankle fractures to test patients' continuous, long-term compliance to partial weight-bearing restrictions and investigate whether patients can estimate their weight-bearing compliance.

MATERIALS AND METHODS

The postoperative gait of 14 patients after operative treatment of Weber B-type ankle fractures was monitored continuously for six weeks (OpenGO, Moticon GmbH, Munich). All patients were instructed and trained by physical therapists on how to maintain partial weight-bearing for this time. Discontinuous (three, six and twelve weeks) clinical (patient questionnaire, visual analogue pain score [VAS]) and radiographic controls were performed.

RESULTS

Despite the set weight-bearing limits, individual ranges for overall weight-bearing (range 5-107% of the contralateral side) and patient activity (range 0-366 min/day) could be shown. A good correlation between weight-bearing and pain was seen (r_s = -0.68; p = <0.0001). Patients significantly underestimated their weight-bearing time over the set limit (2.3 ± 1.4 min/day vs. real: 12.6 ± 5.9 min/day; p < 0.01).

CONCLUSIONS

Standardized aftercare protocols and repeated training alone cannot ensure compliance to postoperative partial weight-bearing. Patients unconsciously increased weight-bearing based on their pain level. This study shows that new, individual and possibly technology-assisted weight-bearing regimes are needed. The introduced measuring device is feasible to monitor and steer patient weight-bearing during future studies.

Lessons about Motor Learning: How Is Motor Learning Taught in Physical Therapy Programmes Across Canada?

Purpose: This article describes the content of and delivery methods for motor learning (ML) education and the attitudes and beliefs of instructors with regard to how ML is taught in Canadian physical therapy (PT) programmes. Method: A qualitative descriptive design was employed, using an online questionnaire and semi-structured telephone interviews. A descriptive content analysis was used to develop codes and themes. An online search of PT programme Web sites was conducted to supplement missing data and collect information from schools that did not participate in the online questionnaire or interview. Results: Eight individuals representing seven schools completed the questionnaire; six of the eight also completed the interview. Responses conveyed the fact that ML content was fairly consistent across schools and was predominantly situated in the neurological curriculum. Schools differed in the delivery methods used for clinical application of ML content. Respondents believed that ML underlies PT practice and should be integrated throughout the programme. Conclusion: Current instruction may deliver adequate ML content but may not provide optimal opportunities to apply ML principles in a clinical context. Continuing education emerged as one suggestion for remediating clinicians' knowledge-practice gap and facilitating student learning on placement. Only half the eligible PT schools participated, and all were English-language programmes; thus, the findings may not be generalizable to all Canadian programmes. Future work should explore how ML can be integrated into the PT curriculum to promote the application of ML principles across different fields. Students' perspectives on their understanding of ML and ML principles and self-efficacy for entry to practice should also be explored.

An Older Adult Study of Concurrent Visual Feedback in Learning Continuous Balance

This investigation manipulated concurrent visual feedback for older adults learning to perform a continuous balance task. We randomly assigned 21 older adults to one of three knowledge of results (KR) groups with varying concurrent but always 100% terminal feedback percentages during acquisition: 100% Concurrent and Terminal (100% C&T), 50% Concurrent and 100% Terminal (50% C & 100% T), and 0% Concurrent and 100% Terminal (0% C & 100% T). The continuous balance task involved learning to maintain balance on a circular platform that moved simultaneously on both anterior/posterior and medial/lateral axes. We tested participants before acquisition phase learning and two days afterwards (retention test). At retention testing, participants in the 50% C & 100% T and those in the 0% C & 100% T conditions demonstrated significantly greater accuracy and stability than did participants in the 100% C&T condition. These findings extend previous research with young adults in supporting the guidance theory that too frequent a provision of concurrent knowledge of results negatively affects learning.

Permissive weight bearing in trauma patients with fracture of the lower extremities: prospective multicenter comparative cohort study

Background

The standard aftercare treatment in surgically treated trauma patients with fractures around or in a joint, known as (peri)- or intra-articular fractures of the lower extremities, is either non-weight bearing or partial weight bearing. We have developed an early permissive weight bearing post-surgery rehabilitation protocol in surgically treated patients with fractures of the lower extremities. In this proposal we want to compare our early permissive weight bearing protocol to the existing current non-weight bearing guidelines in a prospective comparative cohort study.

Methods/design

The study is a prospective multicenter comparative cohort study in which two rehabilitation aftercare treatments will be contrasted, i.e. permissive weight bearing and non-weight bearing according to the AO-guideline. The study population consists of patients with a surgically treated fracture of the pelvis/acetabulum or a surgically treated (peri)- or intra-articular fracture of the lower extremities. The inclusion period is 12 months. The duration of follow up is 6 months, with measurements taken at baseline, 2,6,12 and 26 weeks post-surgery.

Primary outcome measure: ADL with Lower Extremity Functional Scale. Outcome variables for compliance, as measured with an insole pressure measurement system, encompass peak load and step duration.

Discussion

This study will investigate the (cost-) effectiveness of a permissive weight bearing aftercare protocol. The results will provide evidence whether a permissive weight bearing protocol is more effective than the current non-weight bearing protocol.

Trial registration

The study is registered in the Dutch Trial Register (NTR6077). Date of registration: 01–09-2016.

Technology-Based Feedback and Its Efficacy in Improving Gait Parameters in Patients with Abnormal Gait: A Systematic Review

This systematic review synthesized and analyzed clinical findings related to the effectiveness of innovative technological feedback for tackling functional gait recovery. An electronic search of PUBMED, PEDro, WOS, CINAHL, and DIALNET was conducted from January 2011 to December 2016. The main inclusion criteria were: patients with modified or abnormal gait; application of technology-based feedback to deal with functional recovery of gait; any comparison between different kinds of feedback applied by means of technology, or any comparison between technological and non-technological feedback; and randomized controlled trials. Twenty papers were included. The populations were neurological patients (75%), orthopedic and healthy subjects. All participants were adults, bar one. Four studies used exoskeletons, 6 load platforms and 5 pressure sensors. The breakdown of the type of feedback used was as follows: 60% visual, 40% acoustic and 15% haptic. 55% used terminal feedback versus 65% simultaneous feedback. Prescriptive feedback was used in 60% of cases, while 50% used descriptive feedback. 62.5% and 58.33% of the trials showed a significant effect in improving step length and speed, respectively. Efficacy in improving other gait parameters such as balance or range of movement is observed in more than 75% of the studies with significant outcomes.

CONCLUSION

Treatments based on feedback using innovative technology in patients with abnormal gait are mostly effective in improving gait parameters and therefore useful for the functional recovery of patients. The most frequently highlighted types of feedback were immediate visual feedback followed by terminal and immediate acoustic feedback.

Technical Aspects and Validation of a New Biofeedback System for Measuring Lower Limb Loading in the Dynamic Situation

Background: A variety of techniques for measuring lower limb loading exists, each with their own limitations. A new ambulatory biofeedback system was developed to overcome these limitations. In this study, we described the technical aspects and validated the accuracy of this system. Methods: A bench press was used to validate the system in the static situation. Ten healthy volunteers were measured by the new biofeedback system and a dual-belt instrumented treadmill to validate the system in the dynamic situation. Results: Bench press results showed that the sensor accurately measured peak loads up to 1000 N in the static situation. In the healthy volunteers, the load curves measured by the biofeedback system were similar to the treadmill. However, the peak loads and loading rates were lower in the biofeedback system in all participants at all speeds. Conclusions: Advanced sensor technologies used in the new biofeedback system resulted in highly accurate measurements in the static situation. The position of the sensor and the design of the biofeedback system should be optimized to improve results in the dynamic situation.

Biofeedback in Partial Weight Bearing: Usability of Two Different Devices from a Patient's and Physical Therapist's Perspective

Background

Partial weight bearing is frequently instructed by physical therapists in patients after lower-limb trauma or surgery. The use of biofeedback devices seems promising to improve the patient’s compliance with weight-bearing instructions. SmartStep and OpenGo-Science are biofeedback devices that provide real-time feedback. For a successful implementation, usability of the devices is a critical aspect and should be tested from a user’s perspective.

Aim

To describe the usability from the physical therapists’ and a patients’ perspective of Smartstep and OpenGo-Science to provide feedback on partial weight bearing during supervised rehabilitation of patients after lower-limb trauma or surgery.

Methods

In a convergent mixed-methods design, qualitative and quantitative data were collected. Usability was subdivided into user performance, satisfaction and acceptability. Patients prescribed with partial weight bearing and their physical therapists were asked to use SmartStep and OpenGo-Science during supervised rehabilitation. Usability was qualitatively tested by a think-aloud method and a semi-structured interview and quantitatively tested by the System-Usability-Scale (SUS) and closed questions. For the qualitative data thematic content analyses were used.

Results

Nine pairs of physical therapists and their patients participated. The mean SUS scores for patients and physical therapists were for SmartStep 70 and 53, and for OpenGo-Science 79 and 81, respectively. Scores were interpreted with the Curved Grading Scale. The qualitative data showed that there were mixed views and perceptions from patients and physical therapists on satisfaction and acceptability.

Conclusion

This study gives insight in the usability of two biofeedback devices from the patient’s and physical therapist’s perspective. The overall usability from both perspectives seemed to be acceptable for OpenGo-Science. For SmartStep, overall usability seemed only acceptable from the patient’s perspective.

Implication

The study findings could help clinicians to decide which biofeedback device is appropriate for their given situation and provide information for future development of biofeedback devices.

Motor Lateralization Provides a Foundation for Predicting and Treating Non-paretic Arm Motor Deficits in Stroke

Brain lateralization is a ubiquitous feature of neural organization across the vertebrate spectrum. We have developed a model of motor lateralization that attributes different motor control processes to each cerebral hemisphere. This bilateral hemispheric model of motor control has successfully predicted hemisphere-specific motor control and motor learning deficits in the ipsilesional, or non-paretic, arm of patients with unilateral stroke. We now show across large number and range of stroke patients that these motor performance deficits in the non-paretic arm of stroke patients vary with both the side of the lesion, as well as with the severity of contralesional impairment. This last point can be functionally devastating for patients with severe contralesional paresis because for these individuals, performance of upper extremity activities of daily living depends primarily and often exclusively on ipsilesional arm function. We present a pilot study focused on improving the speed and coordination of ipsilesional arm function in a convenience sample of three stroke patients with severe contralesional impairment. Over a three-week period, patients received a total of nine 1.5 h sessions of training that included intense practice of virtual reality and real-life tasks. Our results indicated substantial improvements in ipsilesional arm movement kinematics, functional performance, and that these improvements carried over to improve functional independence. In addition, the contralesional arm improved in our measure of contralesional impairment, which was likely due to improved participation in activities of daily living. We discuss of our findings for physical rehabilitation.

Reliability of the measures of weight-bearing distribution obtained during quiet stance by digital scales in subjects with and without hemiparesis

Described as an alternative way of assessing weight-bearing asymmetries, the measures obtained from digital scales have been used as an index to classify weight-bearing distribution. This study aimed to describe the intra-test and the test/retest reliability of measures in subjects with and without hemiparesis during quiet stance. The percentage of body weight borne by one limb was calculated for a sample of subjects with hemiparesis and for a control group that was matched by gender and age. A two-way analysis of variance was used to verify the intra-test reliability. This analysis was calculated using the differences between the averages of the measures obtained during single, double or triple trials. The intra-class correlation coefficient (ICC) was utilized and data plotted using the Bland-Altman method. The intra-test analysis showed significant differences, only observed in the hemiparesis group, between the measures obtained by single and triple trials. Excellent and moderate ICC values (0.69-0.84) between test and retest were observed in the hemiparesis group, while for control groups ICC values (0.41-0.74) were classified as moderate, progressing from almost poor for measures obtained by a single trial to almost excellent for those obtained by triple trials. In conclusion, good reliability ranging from moderate to excellent classifications was found for participants with and without hemiparesis. Moreover, an improvement of the repeatability was observed with fewer trials for participants with hemiparesis, and with more trials for participants without hemiparesis.

Sonification and haptic feedback in addition to visual feedback enhances complex motor task learning

Concurrent augmented feedback has been shown to be less effective for learning simple motor tasks than for complex tasks. However, as mostly artificial tasks have been investigated, transfer of results to tasks in sports and rehabilitation remains unknown. Therefore, in this study, the effect of different concurrent feedback was evaluated in trunk-arm rowing. It was then investigated whether multimodal audiovisual and visuohaptic feedback are more effective for learning than visual feedback only. Naïve subjects (N = 24) trained in three groups on a highly realistic virtual reality-based rowing simulator. In the visual feedback group, the subject's oar was superimposed to the target oar, which continuously became more transparent when the deviation between the oars decreased. Moreover, a trace of the subject's trajectory emerged if deviations exceeded a threshold. The audiovisual feedback group trained with oar movement sonification in addition to visual feedback to facilitate learning of the velocity profile. In the visuohaptic group, the oar movement was inhibited by path deviation-dependent braking forces to enhance learning of spatial aspects. All groups significantly decreased the spatial error (tendency in visual group) and velocity error from baseline to the retention tests. Audiovisual feedback fostered learning of the velocity profile significantly more than visuohaptic feedback. The study revealed that well-designed concurrent feedback fosters complex task learning, especially if the advantages of different modalities are exploited. Further studies should analyze the impact of within-feedback design parameters and the transferability of the results to other tasks in sports and rehabilitation.

Orthopedic inpatients’ ability to accurately reproduce partial weight bearing orders

Partial weight bearing is often prescribed for patients with orthopedic injuries. Patients’ ability to accurately reproduce partial weight bearing orders is variable, and its impact on clinical outcomes is unknown. This observational study measured patients’ ability to reproduce partial weight bearing orders, factors influencing this, patients’ and physiotherapists’ ability to gauge partial weight bearing accuracy, and the effect of partial weight bearing accuracy on long-term clinical outcomes. Fifty-one orthopedic inpatients prescribed partial weight bearing were included. All received standard medical/nursing/physiotherapy care. Physiotherapists instructed patients in partial weight bearing using the hand-under-foot, bathroom scales, and/or verbal methods of instruction. Weight bearing was measured on up to 3 occasions during hospitalization using a force-sensitive insole. Factors that had the potential to influence partial weight bearing accuracy were recorded. Patients and their physiotherapists rated their perception of partial weight bearing accuracy. Three-month clinical follow-up data were retrieved from medical records. The majority of patients (72% or more) exceeded their target load, with mean peak weight bearing as high as 19.3 kg over target load (285% of target load). Weight bearing significantly increased over the 3 measurement occasions (P<.001) and was significantly associated with greater body weight (P=.04). Patients and physiotherapists were unable to accurately gauge partial weight bearing accuracy. The incidence of clinically important complications at 3 months was 9% and not significantly associated with partial weight bearing accuracy during hospitalization (P≥.45). Patients are unable to accurately reproduce partial weight bearing orders when trained with the hand-under-foot, bathroom scales, or verbal methods of instruction.

Weight bearing after a periarticular fracture: what is the evidence?

Orthopedic surgeons frequently provide weight-bearing recommendations to guide patient recovery following lower extremity fractures. This article discusses the available literature regarding the effects of early weight bearing on fracture healing, patient compliance with weight bearing restrictions, and the effect of different weight bearing protocols following acetabular, tibial plateau, tibial plafond, ankle, and calcaneus fractures.

Terminal feedback outperforms concurrent visual, auditory, and haptic feedback in learning a complex rowing-type task

Augmented feedback, provided by coaches or displays, is a well-established strategy to accelerate motor learning. Frequent terminal feedback and concurrent feedback have been shown to be detrimental for simple motor task learning but supportive for complex motor task learning. However, conclusions on optimal feedback strategies have been mainly drawn from studies on artificial laboratory tasks with visual feedback only. Therefore, the authors compared the effectiveness of learning a complex, 3-dimensional rowing-type task with either concurrent visual, auditory, or haptic feedback to self-controlled terminal visual feedback. Results revealed that terminal visual feedback was most effective because it emphasized the internalization of task-relevant aspects. In contrast, concurrent feedback fostered the correction of task-irrelevant errors, which hindered learning. The concurrent visual and haptic feedback group performed much better during training with the feedback than in nonfeedback trials. Auditory feedback based on sonification of the movement error was not practical for training the 3-dimensional movement for most participants. Concurrent multimodal feedback in combination with terminal feedback may be most effective, especially if the feedback strategy is adapted to individual preferences and skill level.

Augmented visual, auditory, haptic, and multimodal feedback in motor learning: a review

It is generally accepted that augmented feedback, provided by a human expert or a technical display, effectively enhances motor learning. However, discussion of the way to most effectively provide augmented feedback has been controversial. Related studies have focused primarily on simple or artificial tasks enhanced by visual feedback. Recently, technical advances have made it possible also to investigate more complex, realistic motor tasks and to implement not only visual, but also auditory, haptic, or multimodal augmented feedback. The aim of this review is to address the potential of augmented unimodal and multimodal feedback in the framework of motor learning theories. The review addresses the reasons for the different impacts of feedback strategies within or between the visual, auditory, and haptic modalities and the challenges that need to be overcome to provide appropriate feedback in these modalities, either in isolation or in combination. Accordingly, the design criteria for successful visual, auditory, haptic, and multimodal feedback are elaborated.

Design and validation of GCH System 1.0 which measures the weight-bearing exerted on forearm crutches during aided gait

Normally, when the patient's functional recovery involves partial weight-bearing aided walking using forearm crutches, it is not possible to control the amount of weight-bearing objectively that the individuals carry out and its progression. This leads to significant errors in accuracy and, consequently, complications and after effects in pathologies. To compensate for this deficiency, we have set out to design and validate a measurement system and a computerized record of the loads exerted on Canadian crutches in aided walking as well as incorporating a mechanism for acoustic and visual biofeedback that will inform the subject if said charges are correct, so that they are able correct their errors and avoid problems in their recovery. We analyzed the validity and reliability of the system through a concordance study with the AMTI OR6-7-2000 force plate, extensively validated previously, while finding a correlation coefficient of 0.99 with a significance (p<0.001). We have designed and developed a measurement system with a computerized record, analysis and wireless graphical display of real-time data, incorporating a mechanism for acoustic and visual biofeedback to measure the loads exerted on forearm crutches during aided walking. The device, called "GCH System 1.0" is a reliable and valid instrument.

Physical-guidance benefits in learning a complex motor skill

The effects of physical guidance on learning to perform slalom-type movements on a ski-simulator were examined in 22 participants (18 in Experiment 1, 4 in Experiment 2). In Experiment 1, 1 group of participants practiced the task with ski-poles whereas another group practiced without poles. Retention tests without poles were performed at the end of each of the 2 practice days and 1 day later. Although the use of poles produced more effective performance in terms of movement amplitude during practice, both conditions led to similar amplitudes in immediate and delayed retention. With regard to the efficiency of the movement pattern, the pole group demonstrated a more efficient coordination pattern than the no-pole group did, not only during practice but also in immediate (Day 2) and delayed retention. In Experiment 2, how the poles functioned to enhance the learning of a more efficient movement pattern was examined more closely. The results suggest that physical guidance can have beneficial effects not only on performance during practice but also-under certain conditions-on the learning of motor skills.

Extrinsic feedback and management of low back pain: A critical review of the literature

Effective intervention for low back pain (LBP) can include feedback in one form or other. Although extrinsic feedback (EF) can be provided in a number of ways, most research has not considered how different EF characteristics (e.g. timing and content) influence treatment outcomes. A systematic search related to feedback and LBP was performed on relevant electronic databases. This narrative review aims to describe the forms of feedback provision in the literature regarding management of LBP, and to discuss these in light of previously recommended principles for the use of extrinsic feedback. The present review found support for the provision of EF that focuses on content characteristics including program feedback, summary results feedback, and external focus of attention. Temporal characteristics should enhance the use of intermittent or self-selected feedback. The literature does not support the provision of concurrent or constant EF. As much of the literature related to EF in the management of LBP has not considered content and timing characteristics we have identified future research directions that will clarify the use of content and timing characteristics of EF relative to the management of LBP.

Toe-touch weight bearing: myth or reality?

Toe-touch weight bearing and partial weight bearing are commonly prescribed orders. The purpose of this study is to evaluate the validity of toe-touch weight bearing and partial weight bearing regimens. Twenty-five orthopedic surgeons participated in the study. They were asked to answer a questionnaire regarding toe-touch weight bearing and partial weight bearing definitions, and were asked to bear weight partially according to the accepted definitions of each order. Weight bearing on the affected limb was measured by the SmartStep System (Andante Medical Devices, Ltd, Omer, Israel). There was a 40% success rate for toe-touch weight bearing as measured by kilograms and 58% as measured by percentage of body weight. There was a 22% success rate for partial weight bearing as measured by kilograms and 50% success rate as measured by percentage of body weight. For toe-touch weight bearing as measured by kilograms, 52% exerted a mean 15.9 kg more than the maximum. For partial weight bearing as measured by kilograms, 64% exerted too much weight with an average of 14.2 kg more than the maximum. There was a significantly higher success rate for the percentage of body weight order than the kilogram order. The partial weight bearing order with the percent body weight order had a lower mean deviation from desired performance. This study and others demonstrate the need for standardization of weight bearing orders.

Real-time kinematic, temporospatial, and kinetic biofeedback during gait retraining in patients: a systematic review

BACKGROUND

Biofeedback has been used in rehabilitation settings for gait retraining.

PURPOSE

The purpose of this review was to summarize and synthesize the findings of studies involving real-time kinematic, temporospatial, and kinetic biofeedback. The goal was to provide a general overview of the effectiveness of these forms of biofeedback in treating gait abnormalities.

DATA SOURCES

Articles were identified through searches of the following databases: MEDLINE, CINAHL (Cumulative Index to Nursing and Allied Health Literature), and Cochrane Central Register for Controlled Trials. All searches were limited to the English language and encompassed the period from 1965 to November 2007.

STUDY SELECTION

Titles and abstracts were screened to identify studies that met the following requirements: the study included the use of kinematic, temporospatial, or kinetic biofeedback during gait training, and the population of interest showed abnormal movement patterns as a result of a pathology or injury.

DATA EXTRACTION

All articles that met the inclusion criteria were assessed by use of the Methodological Index for Nonrandomized Studies.

DATA SYNTHESIS

Seven articles met the inclusion criteria and were included in the review. Effect sizes were calculated for the primary outcome variables for all studies that provided enough data. Effect sizes generally suggested moderate to large treatment effects for all methods of biofeedback during practice.

LIMITATIONS

Several of the studies lacked adequate randomization; therefore, readers should exercise caution when interpreting authors' conclusions.

CONCLUSIONS

Each biofeedback method appeared to result in moderate to large treatment effects immediately after treatment. However, it is unknown whether the effects were maintained. Future studies should ensure adequate randomization of participants and implementation of motor learning concepts and should include retention testing to assess the long-term success of biofeedback and outcome measures capable of demonstrating coordinative changes in gait and improvement in function.

[Partial weight-bearing in rehabilitation. Strategies for instruction and limitations]

Following trauma or surgery on the musculoskeletal system the primary aim is always as complete a restitution of mobility as possible. By mobilization with partial weight-bearing this is possible. The preferred way of teaching partial weight-bearing is the use of conventional bathroom scales. This method proves to be simple as well as time and cost-saving, but the transferability to the patient's daily life is questionable. Training and control of partial weight-bearing under dynamic conditions, such as normal walking, and walking up and down stairs seem to be very important. Different investigations have shown that the minority of subjects recruited could manage to maintain the given load of partial weight-bearing. Furthermore, the actual resulting moments within the joints, caused by muscles, fascia and tendons, are not considered in presets of partial weight-bearing, as only external forces (ground reaction forces) are measured. However, the problems in teaching partial weight-bearing have to be contrasted with the as yet unexplained issue of postoperative partial versus full weight-bearing.

An Inexpensive Weight Bearing Indicator With Load Range Capability for Rehabilitation of Patients With Lower Extremity Injuries

This paper investigates the mechanical behavior and design of a patent pending device called a load range weight bearing indicator (LWBI), which provides upper and lower range indication to patients with lower extremity injuries as part of a partial weight bearing rehabilitation. The LWBI consists of two opposing stacks (a.k.a. double stack) of snap domes—bistable mechanical elements that snap through only when a threshold weight is applied—sandwiched between a load transfer plate and base plate. The mechanical behavior of a LWBI has been characterized by testing single and double stacks of snap domes in a rigid aluminum fixture using a universal testing machine. Single stacks of two to eight snap domes each exhibited very predictable and repeatable buckling behavior (i.e., stack buckling load is simply the sum of individual snap dome buckling loads) when deflected at speeds typical for patients walking with a regular gait. The double stack configuration only works when supporting legs of the opposing snap dome stacks are offset by half the angle between adjacent legs. The lower load stack buckles first, while the higher load stack buckles at its threshold load because of the very low force required to keep the lower load stack collapsed. While the presence of a spacer has little effect on the double stack buckling behavior under controlled rate deflection in a precision test fixture, it was required for proper functioning of a LWBI prototype probably because of looser dimensional tolerances. The type of substrate that snap dome stacks are in contact with has little effect on the buckling loads as long as the material is not too soft. Finally, the speed of deflection within the expected range of ambulating patients has an insignificant effect on the LWBI’s buckling behavior. A LWBI prototype was designed based on the observed characteristics of the snap dome double stack with a spacer plate between the upper and lower load stacks. The prototype was installed in a recess in the insole of a biomechanical shoe beneath the patient’s heel. The shoe with LWBI was tested by various subjects pushing on a force plate and the upper and lower buckling loads were clearly indicated to the subject by audible and tactile click and measured as ground reaction force versus time. Future work will focus on further testing of the device and refinement of the design for various medical appliances.

No adverse effects of early weight bearing after uncemented total hip arthroplastyA randomized study of 20 patients

BACKGROUND

Few guidelines are available whether early weight-bearing after an uncemented total hip arthroplasty (THA) can be recommended or not. Stability and ingrowth may be jeopardized by immediate loading of the implant while functional recovery may be promoted and periprosthetic demineralization reduced.

PATIENTS AND METHODS

We did a prospective study of 20 patients who were operated on with a hydroxyapatite-coated (HA), uncemented total hip arthroplasty with a tapered stem because of unilateral arthrosis, and randomized the patients to the immediate (I) or late (L) weight-bearing (after 3 months) group. The shoe on the operated side was equipped with an auditory device signaling when the patient placed a load on the extremity. The clinical assessment was done with the Harris hip score at the time of the operation and after 12 and 24 months. Radiographs and dual-energy x-ray absorptiometry (DEXA) were evaluated for migration, femoral remodeling and bone mineral density (BMD) after 3, 6, 12 and 24 months. Tc-scintigraphy was done after 6, 12 and 24 months.

RESULTS

Postoperatively, the Harris hip score showed no group difference. After 3 months, we noted a large reduction in BMD around the stem prosthesis. This was most marked in the proximal regions and the bone loss was significantly larger in zone 1, 4 and 5 in the L group. Distally, the BMD normalized with time, but the loss of bone persisted in the proximal zones after 24 months. An initial increase in the scintigraphic uptake ratio in all zones in both groups declined with time, but it was still increased on the operated side after 24 months. Several radiographic signs of bone remodeling were seen, but the patterns were similar in both groups.

INTERPRETATION

We found no adverse effect of immediate weight bearing with this prosthesis.

Effectiveness of two forms of feedback on training of a joint mobilization skill by using a joint translation simulator

BACKGROUND AND PURPOSE

Joint mobilization is a complicated task to learn and to teach and is characterized by great intersubject variability. This study's purpose was to investigate whether quantitatively augmented feedback could enhance the learning of joint mobilization and, more specifically, to compare the effects of training with concurrent or terminal feedback by using a joint translation simulator (JTS).

SUBJECTS

Thirty-six undergraduate physical therapist students were randomly assigned to control (no feedback), concurrent feedback, and terminal feedback groups.

METHODS

The JTS was designed to simulate tissue resistance based on load-displacement relationships of glenohumeral joint specimens. Subjects applied specific mobilization grades of force on the JTS while quantitative feedback was given to the feedback groups either during a trial (ie, concurrent feedback) or after a trial (ie, terminal feedback). The skill acquisition phase lasted a total of 40 minutes, and a total of 75 repetitions were performed for each grade of each joint model. Pretest and no-feedback retention tests were conducted.

RESULTS

During acquisition and retention, both feedback groups performed more accurately than did the control group. No obviously superior performance was shown by the terminal feedback group compared with concurrent feedback group during retention testing.

DISCUSSION AND CONCLUSION

Subjects who trained with augmented feedback had less variability, and thus more consistency, than the control group subjects who received no feedback. Augmented feedback provides the student with a reference force and the status of his or her performance. The effectiveness of the JTS feedback compared with no feedback was clearly demonstrated. Skill acquisition in mobilization can be enhanced by either concurrent or terminal feedback.

The difference between actual and prescribed weight bearing of total hip patients with a trochanteric osteotomy: long-term vertical force measurements inside and outside the hospital

OBJECTIVE

To determine whether patients load the operated leg at a prescribed weight-bearing target load during postoperative recovery.

DESIGN

A descriptive prospective study.

SETTING

Orthopedic clinic and patients' homes.

PARTICIPANTS

Fifty patients who had undergone total hip arthroplasty (THA) with trochanteric osteotomy.

INTERVENTION

Patients were verbally instructed by a physical therapist to perform partial weight bearing at a 10% body weight (BW) target load (n=33) or at a 50% BW target load (n=17).

MAIN OUTCOME MEASURES

Mean peak load (%BW) and percentage of patients and mean percentage of steps below, equal to, and above the target load. Weight bearing was measured when patients walked with (condition 1) and without (condition 2) a physical therapist in the hospital and walked at home (condition 3).

RESULTS

The mean peak load was significantly higher than the target in the 10% BW group for all 3 conditions (condition 1, 19.2% BW; condition 2, 20.0% BW; condition 3, 26.8% BW). In the 50% BW group, the mean peak load was significantly lower than the target in conditions 1 (28.1% BW) and 2 (32.5% BW). No significant difference in weight bearing was found when walking with or without a physical therapist (change in 10% BW, -0.1% BW; change in 50% BW, -3.17% BW). At home, the mean peak load was significantly larger compared with walking without a physical therapist in the hospital (change in 10% BW, -7.0% BW; change in 50% BW, -11.5% BW).

CONCLUSIONS

Partial weight bearing at a specific target load was not achieved by patients with a THA when given verbal instructions. Especially when using a low target load and when walking at home with no supervision of a physical therapist, patients loaded the operated leg higher and more frequently above the target load. Other training methods (eg, biofeedback) have to be evaluated to use as training tools for partial weight bearing at specific target loads.

Extrinsic feedback for motor learning after stroke: what is the evidence?

PURPOSE

There is little guidance on using extrinsic feedback to enhance motor learning after stroke. This narrative review synthesises research findings and identifies questions remaining to be answered.

METHOD

A summary is given relating to the use of extrinsic feedback in healthy subjects. Then, research concerning content of feedback, feedback scheduling, and attentional focus is discussed in relation to patients with stroke.

RESULTS

Though research is scarce, preliminary key findings were as follows: Patients' balance performance can improve from receiving visual feedback about weight distribution during practice; auditory feedback of force production may improve performance of sit-to-stand; providing feedback on less than 100% of trials, and giving summary or average feedback may enhance learning; instructions or feedback inducing an external focus may be more effective than those with an internal focus. Further research is needed concerning the relative benefits of verbal, visual, video and kinematic feedback; reduced feedback frequencies and summary feedback schedules; feedback delays, error estimation, and self-controlled feedback; and attentional focus of feedback.

CONCLUSIONS

Although there are some indications that feedback might enhance motor learning after stroke, there are many areas as yet not examined and there is clearly a need for considerable research in this area.

An Inexpensive Weight Bearing Indicator Used for Rehabilitation of Patients With Lower Extremity Injuries

Background. Partial or nonweight bearing is a useful treatment prescribed by medical professionals (e.g., orthopedists, podiatrists) for patients rehabilitating from lower extremity injuries However, there is significant variability in patient conformance with the commonly used, but very imprecise “weight scale method.” Furthermore, the few commercially available load monitoring devices are rarely used because of their high cost. Method of Approach. As a simple and inexpensive alternative to current load monitoring methods and commercial products, a new medical device called a snap dome weight bearing indicator (WBI) has been developed to gently warn a patient when they have exceeded a limited percentage of their body weight on the recovering leg or foot. When installed in a patient’s shoe or medical appliance, the device does so by utilizing the reversible buckling phenomena of a snap dome to provide a tactile and audible feedback when the prescribed weight has been exceeded. To demonstrate the feasibility of this new device, the performance of (1) the snap dome by itself and (2) several WBI designs developed were tested. The most useful of the new designs include one incorporating a heel cup for loose fitting medical appliances and a podiatric off-loading indicator (POLI). In addition, a pilot study and manufacturing cost analysis of the POLI device were performed to investigate patient usability and affordability issues. Results. The particular four-leg snap domes used in device prototypes performed quite well with regards to buckling load consistency between domes, the linearity of buckling load by stacking domes in a parallel arrangement, and buckling load repeatability of a single dome. The performance of each WBI prototype was tested with regards to load transfer, tactile, and audible feedback to the patient, patient comfort, and ease of installation. Prototype performance was generally very good or excellent except for the POLI device, which does not provide sufficient tactile or audible feedback for many patients. A costing analysis of the POLI device suggests that it can be manufactured in the U.S. for around one dollar. Conclusions. The generally positive results from performance testing of commercially available snap domes and WBI prototypes suggest that this new medical device will indeed be an inexpensive, yet effective conformance tool for orthopedists and podiatrists to use in prescribing partial or no weight bearing for a patient.

Effects of Age and Timing of Augmented Feedback on Learning Muscle Relaxation While Performing a Gross Motor Task

OBJECTIVE

To examine the combined effect of age and timing of augmented feedback on learning muscle relaxation. Performing a gross motor task, subjects had to lower their trapezius muscle activity using the electromyographic signal as visual myofeedback.

DESIGN

Healthy subjects (16 young adults: 20-35 yrs; and 16 older adults: 55-70 yrs) were randomly assigned to one of two timing conditions of myofeedback: concurrent (feedback was provided immediately during the trial) and terminal (feedback was provided delayed after the trial) condition.

RESULTS

The results indicated that young adults had a higher level of motor performance (i.e., lower muscle activity) compared with older adults when myofeedback was provided. These effects persisted during short- (after 10 mins) and long-term retention (after 1 wk) when no myofeedback was provided. In contrast to young adults, older adults did not improve their performance throughout the experiment. There were no interactions of age with the timing conditions of myofeedback during acquisition and retention.

CONCLUSIONS

Either timing condition of augmented feedback was equally helpful to young adults, whereas neither was helpful for older adults in learning muscle relaxation.

Reproducibilty of partial weight bearing

OBJECTIVES

To find out whether partial weight bearing can be reproduced and retained.

DESIGN

In vivo experiment in normal subjects.

INTERVENTION

Training for partial weight bearing (25% of body weight) using bathroom scales.

MAIN OUTCOME MEASUREMENT

Reproducibility on force platform immediately after training and after 60 min.

RESULTS

Twelve subjects were asked to reproduce 25% of their body weight through either the dominant or non-dominant limb on force platform after three practice attempts on bathroom scales with concurrent visual feedback. No feedback was provided after the measurements on force plate. The process was repeated after 1h without any practice sessions in the interim period to find out if the weight practised could be retained. The mean 0-min reading was found to be 25.9% of body weight while the mean 60-min reading was found to be 24.4%. The p-value for the difference between the two means was found to be 0.3841.

CONCLUSIONS

This study indicates that partial weight bearing instructions can be quantified and graded. Simple bathroom scales are sufficient to educate the patients and this can be practised at home after an initial period of supervision.