Biofeedback improves performance in lower limb activities more than usual therapy in people following stroke: a systematic review

A metric for characterizing the arm nonuse workspace in poststroke individuals using a robot arm

An overreliance on the less-affected limb for functional tasks at the expense of the paretic limb and in spite of recovered capacity is an often-observed phenomenon in survivors of hemispheric stroke. The difference between capacity for use and actual spontaneous use is referred to as arm nonuse. Obtaining an ecologically valid evaluation of arm nonuse is challenging because it requires the observation of spontaneous arm choice for different tasks, which can easily be influenced by instructions, presumed expectations, and awareness that one is being tested. To better quantify arm nonuse, we developed the bimanual arm reaching test with a robot (BARTR) for quantitatively assessing arm nonuse in chronic stroke survivors. The BARTR is an instrument that uses a robot arm as a means of remote and unbiased data collection of nuanced spatial data for clinical evaluations of arm nonuse. This approach shows promise for determining the efficacy of interventions designed to reduce paretic arm nonuse and enhance functional recovery after stroke. We show that the BARTR satisfies the criteria of an appropriate metric for neurorehabilitative contexts: It is valid, reliable, and simple to use.

Flexibility for Intensity Dosing in Lingual Resistance Exercises: A Large Randomized Clinical Trial in Typically Aging Adults as Proof of Principle

OBJECTIVE

The objective of this study was to determine the effect of intensity dosing during tongue exercise on tongue pressure generation, adherence, and perceived effort.

DESIGN

This was a five-site, prospective, randomized clinical trial. Outcome measures were obtained across multiple baselines, biweekly during exercise, and 4-weeks post-intervention.

SETTING

The general community at each study site.

PARTICIPANTS

Typically aging adults between 55-82 years of age with no history of neurological or swallowing disorders. Eighty-four volunteers completed the study.

INTERVENTIONS

Participants were randomly assigned to one of four exercise groups: (a) maximum intensity/no biofeedback, (b) progressive intensity/no biofeedback, (c) maximum intensity/biofeedback, and (d) progressive intensity/biofeedback. Half of the participants completed a maintenance exercise program.

OUTCOME MEASURES

Maximum isometric pressure (MIP), regular effort saliva swallow pressure, adherence, and the Borg Rating of Perceived Exertion Scale.

RESULTS

All exercise protocols were efficacious for gains in MIP (large effect sizes; Cohen's d). Group 3 made gains in regular effort saliva swallow pressure (medium effect size). There was a significant change in perceived exertion for regular effort saliva swallow pressure at 8 weeks. Tongue pressure gains were maintained at 1 month, regardless of maintenance group status. Mean adherence across groups was high.

CONCLUSIONS

All groups improved pressure generation. Intensity dosing differences did not affect strength gains, adherence, or detraining. Regular effort saliva swallow pressure may be most responsive to maximum intensity with biofeedback. The findings suggest flexibility in approach to tongue exercise protocols. Tongue muscles may differ from limb muscles in terms of dose response and neuroplasticity principles.

Biofeedback interventions for short term upper limb function following stroke: A systematic review with meta-analysis

BACKGROUND

Biofeedback has been used by rehabilitation professionals in the treatment of poststroke function impairments.

PURPOSE

Investigate the efficacy of any type of biofeedback intervention for the treatment of upper limb function in individuals following stroke.

STUDY DESIGN

Systematic review of literature with meta-analysis.

METHODS

Literature searches were conducted using MESH terms and text words in PubMed, Lilacs, Scielo, Scopus, PEDro, and Web of Science databases. The main outcome was improvement in upper limb's motor function and motor function in activities of daily living. We calculated the Mean Difference and Standardized Mean Difference for the assessment scales reported as primary outcome. The methodological quality of included studies was assessed using PEDro scale. The overall quality of the evidence was assessed using GRADE system.

RESULTS

From 1360 articles identified, 16 were included in the review (09 in the meta-analysis). Three forest plots of hemiparesis and one of hemiplegia showed that biofeedback therapy associated with conventional therapy has a greater improvement in participants upper limb motor function when compared to isolated conventional therapy. Two forest plots of hemiparesis and one of hemiplegia showed no superiority in participants improvement for biofeedback associated with conventional therapy when compared to isolated conventional therapy.

CONCLUSION

Biofeedback therapy associated with conventional therapy showed a small clinical effect when associated to conventional therapy and very low quality of evidence. Although further research with higher quality evidence is needed.

The Application of Soft Robotic Gloves in Stroke Patients: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Wearable robotic devices have been strongly put into use in both the clinical and research fields of stroke rehabilitation over the past decades. This study aimed to explore the effectiveness of soft robotic gloves (SRGs) towards improving the motor recovery and functional abilities in patients with post-stroke hemiparesis. Five major bibliographic databases, PubMed, Embase, Cochrane Library, Web of Science, and the Physiotherapy Evidence Database, were all reviewed for enrollment regarding comparative trials prior to 7 March 2023. We included adults with stroke and compared their rehabilitation using SRGs to conventional rehabilitation (CR) on hand function in terms of the Fugl-Meyer Upper Extremity Motor Assessment (FMA-UE), Fugl-Meyer Distal Upper Extremity Motor Assessment (FMA-distal UE), box and blocks test score, grip strength test, and the Jebsen-Taylor hand function test (JTT). A total of 8 studies, comprising 309 participants, were included in the analysis. Compared to CR, rehabilitation involving SRGs achieved better FMA-UE (MD 6.52, 95% CI: 3.65~9.39), FMA-distal UE (MD 3.27, 95% CI: 1.50~5.04), and JJT (MD 13.34, CI: 5.16~21.53) results. Subgroup analysis showed that stroke latency of more than 6 months and training for more than 30 min offered a better effect as well. In conclusion, for patients with stroke, rehabilitation using SRGs is recommended to promote the functional abilities of the upper extremities.

A 3D-Printed Soft Haptic Device with Built-in Force Sensing Delivering Bio-Mimicked Feedback

Haptics plays a significant role not only in the rehabilitation of neurological disorders, such as stroke, by substituting necessary cognitive information but also in human-computer interfaces (HCIs), which are now an integral part of the recently launched metaverse. This study proposes a unique, soft, monolithic haptic feedback device (SoHapS) that was directly manufactured using a low-cost and open-source fused deposition modeling (FDM) 3D printer by employing a combination of soft conductive and nonconductive thermoplastic polyurethane (TPU) materials (NinjaTek, USA). SoHapS consists of a soft bellow actuator and a soft resistive force sensor, which are optimized using finite element modeling (FEM). SoHapS was characterized both mechanically and electrically to assess its performance, and a dynamic model was developed to predict its force output with given pressure inputs. We demonstrated the efficacy of SoHapS in substituting biofeedback with tactile feedback, such as gripping force, and proprioceptive feedback, such as finger flexion-extension positions, in the context of teleoperation. With its intrinsic properties, SoHapS can be integrated into rehabilitation robots and robotic prostheses, as well as augmented, virtual, and mixed reality (AR/VR/MR) systems, to induce various types of bio-mimicked feedback.

Effect of Treadmill Training with Visual Biofeedback on Selected Gait Parameters in Subacute Hemiparetic Stroke Patients

BACKGROUND

Functional limitations after a stroke are unique to each person and often include impaired independent mobility. A reduction in existing gait deficits after a stroke is often one of the main goals of rehabilitation. Gait re-education after stroke is a complex process, which consists of the effects of many therapeutic interventions.

OBJECTIVE

The study aimed to analyze the effects of using a treadmill with visual feedback in gait re-education in the sub-acute stroke period and assess the impact of biofeedback treadmill training on selected gait parameters, improving static balance and reducing the need for orthopedic aids.

METHODS

The study included 92 patients (F: 45, M: 47) aged 63 ± 12 years, with post-ischemic sub-acute (within six months onset) stroke hemiparesis, treated at a neurological rehabilitation ward. All patients participated in a specific rehabilitation program, and in addition, patients in the study group (n = 62) have a further 10 min of treadmill training with visual feedback. Patients in the control group (n = 30) participated in additional conventional gait training under the direct supervision of a physiotherapist. The evaluation of static balance was assessed with the Romberg Test. A Biodex Gait Trainer 3 treadmill with biofeedback function was used to evaluate selected gait parameters (walking speed, step length, % limb loading, and traveled distance). The use of an orthopedic aid (walker or a crutch) was noted.

RESULTS

After four weeks of rehabilitation, step length, walking speed, traveled distance, and static balance were significantly improved for the study and control group (p < 0.05). Treadmill gait training yielded significantly better results than a conventional rehabilitation program. Only the study group observed a corrected walking base (p < 0.001). All participants showed a reduction in the use of walking aids (p = 0.006). There was no asymmetry in the % of limb loading for either group prior to or following rehabilitation.

CONCLUSIONS

The treadmill with visual biofeedback as conventional gait training has resulted in a significant improvement in parameters such as step length, walking speed, static balance, and a reduction in the use of locomotion aids. However, the achieved improvement in gait parameters is still not in line with the physiological norm.

Robotic Biofeedback for Post-Stroke Gait Rehabilitation: A Scoping Review

This review aims to recommend directions for future research on robotic biofeedback towards prompt post-stroke gait rehabilitation by investigating the technical and clinical specifications of biofeedback systems (BSs), including the complementary use with assistive devices and/or physiotherapist-oriented cues. A literature search was conducted from January 2019 to September 2022 on Cochrane, Embase, PubMed, PEDro, Scopus, and Web of Science databases. Data regarding technical (sensors, biofeedback parameters, actuators, control strategies, assistive devices, physiotherapist-oriented cues) and clinical (participants' characteristics, protocols, outcome measures, BSs' effects) specifications of BSs were extracted from the relevant studies. A total of 31 studies were reviewed, which included 660 stroke survivors. Most studies reported visual biofeedback driven according to the comparison between real-time kinetic or spatiotemporal data from wearable sensors and a threshold. Most studies achieved statistically significant improvements on sensor-based and clinical outcomes between at least two evaluation time points. Future research should study the effectiveness of using multiple wearable sensors and actuators to provide personalized biofeedback to users with multiple sensorimotor deficits. There is space to explore BSs complementing different assistive devices and physiotherapist-oriented cues according to their needs. There is a lack of randomized-controlled studies to explore post-stroke stage, mental and sensory effects of BSs.

Update on Stroke Rehabilitation in Motor Impairment

Motor impairment due to stroke limits patients' mobility, activities of daily living, and negatively affects their return to the workplace. It also reduces patients' quality of life and increases the socioeconomic burden of stroke. Therefore, optimizing the recovery of motor impairment after stroke is a very important goal for both individuals and society as a whole. The emergence and improvement of various technologies in the Fourth Industrial Revolution have exerted a major influence on the development of new rehabilitation methods and efficiency enhancements for existing methods. This review categorizes rehabilitation methods that promote the recovery of motor function into upper limb function and lower limb function and summarizes recent advances in stroke rehabilitation. Although debate continues regarding the effects of some rehabilitation therapies, it is hoped that the evidence will be improved through ongoing research so that clinicians can treat patients with a higher level of evidence.

Novel Soft Haptic Biofeedback-Pilot Study on Postural Balance and Proprioception

Sensory feedback is critical in proprioception and balance to orchestrate muscles to perform targeted motion(s). Biofeedback plays a significant role in substituting such sensory data when sensory functions of an individual are reduced or lost such as neurological disorders including stroke causing loss of sensory and motor functions requires compensation of both motor and sensory functions. Biofeedback substitution can be in the form of several means: mechanical, electrical, chemical and/or combination. This study proposes a soft monolithic haptic biofeedback device prototyped and pilot tests were conducted with healthy participants that balance and proprioception of the wearer were improved with applied mechanical stimuli on the lower limb(s). The soft monolithic haptic biofeedback device has been developed and manufactured using fused deposition modelling (FDM) that employs soft and flexible materials with low elastic moduli. Experimental results of the pilot tests show that the soft haptic device can effectively improve the balance of the wearer as much as can provide substitute proprioceptive feedback which are critical elements in robotic rehabilitation.

Foot angular kinematics measured with inertial measurement units: A reliable criterion for real-time gait event detection

Accurate and reliable real-time detection of gait events using inertial measurement units (IMUs) is crucial for (1) developing clinically meaningful gait parameters to differentiate normal and impaired gait or (2) creating patient-tailored gait rehabilitation strategies or control of prosthetic devices using feedback from gait phases. However, most previous studies focused only on algorithms with high temporal accuracy and neglected the importance of (1) high reliability, i.e., detecting only and all true gait events, and (2) real-time implementation. Thus, in this study, we presented a novel approach for initial contact (IC) and terminal contact (TC) detection in real-time based on the measurement of the foot orientation. Unlike foot/shank angular velocity and acceleration, foot orientation provides physiologically meaningful kinematic features corresponding to our observational recognition of IC and TC, regardless of the walking modality. We conducted an experimental study to validate our algorithm, including seven participants performing four walking/running activities. By analyzing 5,555 ICs/TCs recorded during the tests, only our algorithm achieved a sensitivity and precision of 100%. Our obtained temporal accuracy (mean ± standard deviation of errors ranging from 0 ± 3 to 6 ± 5 time samples; sampling frequency: 100 Hz) was better than or comparable to those reported in the literature. Our algorithm's performance does not depend on thresholds and gait speed/modality, and it can be used for feedback-based therapeutic gait training or real-time control of assistive or prosthetic technologies. Nevertheless, its performance for pathological gait must be validated in the future. Finally, we shared the codes and sample data on https://www.ncbl.ualberta.ca/codes.

Investigation of optimal gait speed for motor learning of walking using the vibro-tactile biofeedback system

In stroke patients, sensory loss often reduces the sensation of ground contact, which impairs motor learning during rehabilitation. In our previous study, we proposed a vibro-tactile biofeedback system (which we called the perception-empathy biofeedback system) for gait rehabilitation. The results of our 9-week pilot clinical test suggested that patients who had reached the autonomous phase in gait learning had difficulty noticing the external vibratory feedback provided by the biofeedback system, leading to ineffective intervention. We considered the possibility that slower walking speed might return the patient to the association phase and allow patients to improve their gait according to the sensory feedback provided. Thus, in this research, a method based on reducing walking speed to guide patients' attention was derived. A pilot clinical trial shows that there is a statistically significant increase of ankle dorsiflexion in the initial contact phase and increase of ankle plantarflexion in the push-off phase after vibro-tactile biofeedback system intervention with speed reduction, compared to intervention without speed reduction. The results suggest that, by reducing their walking speed during intervention, patients return to the association phase and recognize external vibratory feedback, which may result in better intervention effects.Clinical Relevance-This study provides knowledge about the optimal walking speed when using vibro-tactile biofeedback for motor learning in stroke patients.

Comparison of the Immediate Effects of Audio, Visual, or Audiovisual Gait Biofeedback on Propulsive Force Generation in Able-Bodied and Post-stroke Individuals

Real-time biofeedback is a promising post-stroke gait rehabilitation strategy that can target specific gait deficits preferentially in the paretic leg. Our previous work demonstrated that the use of an audiovisual biofeedback interface designed to increase paretic leg propulsion, measured via anterior ground reaction force (AGRF) generation during late stance phase of gait, can induce improvements in peak AGRF production of the targeted and paretic limb of able-bodied and post-stroke individuals, respectively. However, whether different modes of biofeedback, such as visual, auditory, or a combination of both, have differential effects on AGRF generation is unknown. The present study investigated the effects of audio only, visual only, or audiovisual AGRF biofeedback in able-bodied and post-stroke individuals. Seven able-bodied (6 females, 27 ± 2 years) and nine post-stroke individuals (6 females, 54 ± 12 years, 42 ± 26 months post-stroke) completed four 30-s walking trials on a treadmill under 4 conditions: no biofeedback, audio biofeedback, visual biofeedback, or audiovisual biofeedback. Compared to walking without biofeedback, all three biofeedback modes significantly increased peak AGRF in the targeted and paretic leg. There was no significant difference in peak AGRF between the three biofeedback modes. Able-bodied individuals demonstrated greater feedback-induced increase in stride-to-stride variation of AGRF generation during audio biofeedback compared to visual biofeedback; however, similar results were not observed in the post-stroke group. The present findings may inform future development of real-time gait biofeedback interfaces for use in clinical or community environments.

Differentiation among bio- and augmented- feedback in technologically assisted rehabilitation

Introduction: In rehabilitation practice, the term 'feedback' is often improperly used, with augmented feedback and biofeedback frequently confused, especially when referring to the human-machine interaction during technologically assisted training. The absence of a clear differentiation between these categories represents an unmet need for rehabilitation, emphasized by the advent of new technologies making extensive use of video feedback, exergame, and virtual reality.Area covered: In this review we tried to present scientific knowledge about feedback, biofeedback, augmented feedback and neurofeedback, and related differences in rehabilitation settings, for a more proper use of this terminology. Despite the continuous expansion of the field, few researches clarify the differences among these terms. This scoping review was conducted through the searching of current literature up to May 2020, using following databases: PUBMED, EMBASE and Web of Science. After literature search a classification system, distinguishing feedback, augmented feedback, and biofeedback, was applied.Expert opinion: There is a need for clear definitions of feedback, biofeedback, augmented feedback, and neurofeedback in rehabilitation, especially in the technologically assisted one based on human-machine interaction. In fact, the fast development of new technologies requires to be based on solid concepts and on a common terminology shared among bioengineers and clinicians.

Biofeedback for Post-stroke Gait Retraining: A Review of Current Evidence and Future Research Directions in the Context of Emerging Technologies

Real-time gait biofeedback is a promising rehabilitation strategy for improving biomechanical deficits in walking patterns of post-stroke individuals. Because wearable sensor technologies are creating avenues for novel applications of gait biofeedback, including use in tele-health, there is a need to evaluate the state of the current evidence regarding the effectiveness of biofeedback for post-stroke gait training. The objectives of this review are to: (1) evaluate the current state of biofeedback literature pertaining to post-stroke gait training; and (2) determine future research directions related to gait biofeedback in context of evolving technologies. Our overall goal was to determine whether gait biofeedback is effective at improving stroke gait deficits while also probing why and for whom gait biofeedback may be an efficacious treatment modality. Our literature review showed that the effects of gait biofeedback on post-stroke walking dysfunction are promising but are inconsistent in methodology and therefore results. We summarize sources of methodological heterogeneity in previous literature, such as inconsistencies in feedback target, feedback mode, dosage, practice structure, feedback structure, and patient characteristics. There is a need for larger-sample studies that directly compare different feedback parameters, employ more uniform experimental designs, and evaluate characteristics of potential responders. However, as these uncertainties in existing literature are resolved, the application of gait biofeedback has potential to extend neurorehabilitation clinicians' cues to individuals with post-stroke gait deficits during ambulation in clinical, home, and community settings, thereby increasing the quantity and quality of skilled repetitions during task-oriented stepping training. In addition to identifying gaps in previous research, we posit that future research directions should comprise an amalgam of mechanism-focused and clinical research studies, to develop evidence-informed decision-making guidelines for gait biofeedback strategies that are tailored to individual-specific gait and sensorimotor impairments. Wearable sensor technologies have the potential to transform gait biofeedback and provide greater access and wider array of options for clinicians while lowering rehabilitation costs. Novel sensing technologies will be particularly valuable for telehealth and home-based stepping exercise programs. In summary, gait biofeedback is a promising intervention strategy that can enhance efficacy of post-stroke gait rehabilitation in both clinical and tele-rehabilitation settings and warrants more in-depth research.

A Haptic-Based Perception-Empathy Biofeedback System with Vibration Transition: Verifying the Attention Amount

In this paper, a perception-empathy biofeedback (PEBF) system is proposed that supplements the foot pressure status of a paralyzed foot with a wearable vibrotactile biofeedback (BF) vest to the back. Improvements in the ankle dorsiflexion and push-off movement in the swing phase and pre-swing phase, respectively, can be expected after using the proposed system. However, the results of the 3 week pilot clinical tests suggest that significant improvement is only observed for the push-off movement. It is assumed that the attention required to recognize the BF was beyond the ability of the patients. In this paper, a dual task (40 s walking and performing mental arithmetic at the same time) was conducted with the following conditions: no vibrations and providing BF to the lower back and the entire back. According to the results, the ankle joint angle of the paralyzed side at push-off under the entire back condition is statistically significant (p = 0.0780); however, there are no significant changes under the lower back condition (p = 0.4998). Moreover, the ankle joint angle of the paralyzed side at the initial contact is statistically significant with respect to the lower back condition (p = 0.0233) and shows a significant trend for the entire back condition (p = 0.0730). The results suggest that the limited attention capacity of hemiplegic patients fails to improve both dorsiflexion and push-off movements; moreover, ankle motion can be promoted if attention is concentrated on recognizing focalized vibratory feedback patterns.

An electroencephalography (EEG) study of short-term electromyography (EMG) biofeedback training in patients with myofascial pain syndrome in the upper trapezius

[Purpose] In the present study, electroencephalography was used to explore neural activity related to electromyography biofeedback training, focusing on pain perception before and after electromyography biofeedback. [Participants and Methods] Twenty-seven participants (female=23; mean age: 28.85 ± 4.99 years) with mild-to-moderate myofascial pain syndrome in the upper trapezius were recruited for this study. All participants underwent electroencephalography recording before, during, and after (0 and 15 min) electromyography biofeedback training. Quantitative electroencephalography analysis was performed to obtain the absolute power of the four main frequency bands. Pain scores before and after electromyography biofeedback were also evaluated by subjective rating. [Results] Electromyography biofeedback increased alpha power and decreased delta power 15 minutes after training, suggestive of relaxation. However, although a tendency for scores to decrease was observed, no significant improvements in pain scores were observed following the intervention. Such results may be due to the short duration of the biofeedback session and the subjective nature of pain assessments. [Conclusion] Despite no obvious changes in pain perception, brief electromyography biofeedback training may induce relaxation in patients with myofascial pain syndrome of the upper trapezius muscle.

Use of real-time visual feedback during overground walking training on gait symmetry and velocity in patients with post-stroke hemiparesis: randomized controlled, single-blind study

This study aimed to determine the efficacy of using real-time visual feedback during overground walking training to improve walking function in patients with post-stroke hemiparesis. Twenty-four patients with post-stroke hemiparesis who were able to walk independently under less impact of synergy pattern on the affected lower limbs (Brunnstrom stage IV or V) were randomly assigned to either the experimental group or the control group. All subjects performed overground walking for 30 min, three times a week for 6 weeks, with real-time visual feedback (weight load to the affected lower limb) provided during training for subjects in the experimental group. Outcome measures comprised the timed up-and-go test and gait parameters (step length, stride length, single and double support times, step and stride length ratios, and single support time ratio). In between-group comparison, the changes between pre-test and post-test scores in all parameters were significantly greater in the experimental group than in the control group (P < 0.05), except for double support time and step length ratio. Furthermore, post-test values of all parameters were significantly more improved in the experimental group than in the control group (P < 0.05). Our findings suggest that real-time visual feedback may be an advantageous therapeutic adjunct to reinforce the effects of overground walking training in patients with post-stroke hemiparesis.

Efficacy of Biofeedback for Medical Conditions: an Evidence Map

BACKGROUND

Biofeedback is increasingly used to treat clinical conditions in a wide range of settings; however, evidence supporting its use remains unclear. The purpose of this evidence map is to illustrate the conditions supported by controlled trials, those that are not, and those in need of more research.

METHODS

We searched multiple data sources (MEDLINE, PsycINFO, CINAHL, Epistemonikos, and EBM Reviews through September 2018) for good-quality systematic reviews examining biofeedback for clinical conditions. We included the highest quality, most recent review representing each condition and included only controlled trials from those reviews. We relied on quality ratings reported in included reviews. Outcomes of interest were condition-specific, secondary, and global health outcomes, and harms. For each review, we computed confidence ratings and categorized reported findings as no effect, unclear, or insufficient; evidence of a potential positive effect; or evidence of a positive effect. We present our findings in the form of evidence maps.

RESULTS

We included 16 good-quality systematic reviews examining biofeedback alone or as an adjunctive intervention. We found clear, consistent evidence across a large number of trials that biofeedback can reduce headache pain and can provide benefit as adjunctive therapy to men experiencing urinary incontinence after a prostatectomy. Consistent evidence across fewer trials suggests biofeedback may improve fecal incontinence and stroke recovery. There is insufficient evidence to draw conclusions about effects for most conditions including bruxism, labor pain, and Raynaud's. Biofeedback was not beneficial for urinary incontinence in women, nor for hypertension management, but these conclusions are limited by small sample sizes and methodologic limitations of these studies.

DISCUSSION

Available evidence suggests that biofeedback is effective for improving urinary incontinence after prostatectomy and headache, and may provide benefit for fecal incontinence and balance and stroke recovery. Further controlled trials across a wide range of conditions are indicated.

Haptic biofeedback induces changes in ankle push-off during walking

BACKGROUND

Ankle push-off drives forward progression during gait. Reduced peak ankle moment and peak ankle power may contribute to the increased metabolic cost of walking observed in certain clinical populations. Biofeedback is an effective gait training tool, however biofeedback targeting ankle moment has not been previously studied.

RESEARCH QUESTION

Does haptic biofeedback directly targeting ankle moment enable able-bodied adults to modulate peak ankle moment during gait?

METHODS

20 able-bodied adults participated in the study. Participants completed a 90-second baseline walking trial, followed by two 2-minute trials with haptic biofeedback. Haptic biofeedback guided participants to either increase peak ankle moment (Feedback High), or decrease peak ankle moment (Feedback Low). Ten participants received haptic biofeedback alone; the other ten participants additionally received verbal suggestions of movement strategies they could adopt during the biofeedback trials. Two-way analysis of variance was used to determine the effect of walking condition and verbal instruction on key gait parameters.

RESULTS

A main effect of walking condition on peak ankle moment and peak ankle power was observed (all P < 0.001). Peak ankle moment did not change from baseline during Feedback High, however peak ankle power was increased (P < 0.001). A decrease in peak ankle moment and peak ankle power was observed during Feedback Low (all P < 0.001). Verbal instruction had a significant interaction effect with walking condition in only a limited number of parameters (all P < 0.05).

SIGNIFICANCE

This study demonstrates the effects of haptic biofeedback targeting peak ankle moment during gait. While this study demonstrates that able-bodied individuals have some capacity to modulate their gait pattern in response to direct biofeedback on ankle moment, further investigation is required to develop a biofeedback paradigm that can increase peak ankle moment.

The effect of surface electromyography biofeedback on the activity of extensor and dorsiflexor muscles in elderly adults: a randomized trial

Surface electromyography-biofeedback (sEMG-B) is a technique employed for the rehabilitation of patients with neurological pathologies, such as stroke-derived hemiplegia; however, little is known about its effectiveness in the rehabilitation of the extension and flexion of several muscular groups in elderly patients after a stroke. Therefore, this research was focused on determining the effectiveness of sEMG-B in the muscles responsible for the extension of the hand and the dorsiflexion of the foot in post-stroke elderly subjects. Forty subjects with stroke-derived hemiplegia were randomly divided into intervention or control groups. The intervention consisted of 12 sEMG-B sessions. The control group underwent 12 weeks (24 sessions) of conventional physiotherapy. Muscle activity test and functionality (Barthel index) were determined. Attending to the results obtained, the intervention group showed a higher increase in the average EMG activity of the extensor muscle of the hand and in the dorsal flexion of the foot than the control group (p < 0.001 in both cases), which was associated with an increase in the patients' Barthel index score (p = 0.006); In addition, Fugl-Meyer test revealed higher effectiveness in the lower limb (p = 0.007). Thus, the sEMG-B seems to be more effective than conventional physiotherapy, and the use of this technology may be essential for improving muscular disorders in elderly patients with physical disabilities resulting from a stroke.

Influences of the biofeedback content on robotic post-stroke gait rehabilitation: electromyographic vs joint torque biofeedback

Background

Add-on robot-mediated therapy has proven to be more effective than conventional therapy alone in post-stroke gait rehabilitation. Such robot-mediated interventions routinely use also visual biofeedback tools. A better understanding of biofeedback content effects when used for robotic locomotor training may improve the rehabilitation process and outcomes.

Methods

This randomized cross-over pilot trial aimed to address the possible impact of different biofeedback contents on patients’ performance and experience during Lokomat training, by comparing a novel biofeedback based on online biological electromyographic information (EMGb) versus the commercial joint torque biofeedback (Rb) in sub-acute non ambulatory patients.

12 patients were randomized into two treatment groups, A and B, based on two different biofeedback training. For both groups, study protocol consisted of 12 Lokomat sessions, 6 for each biofeedback condition, 40 min each, 3 sessions per week of frequency. All patients performed Lokomat trainings as an add-on therapy to the conventional one that was the same for both groups and consisted of 40 min per day, 5 days per week. The primary outcome was the Modified Ashworth Spasticity Scale, and secondary outcomes included clinical, neurological, mechanical, and personal experience variables collected before and after each biofeedback training.

Results

Lokomat training significantly improved gait/daily living activity independence and trunk control, nevertheless, different effects due to biofeedback content were remarked. EMGb was more effective to reduce spasticity and improve muscle force at the ankle, knee and hip joints. Robot data suggest that Rb induces more adaptation to robotic movements than EMGb. Furthermore, Rb was perceived less demanding than EMGb, even though patient motivation was higher for EMGb. Robot was perceived to be effective, easy to use, reliable and safe: acceptability was rated as very high by all patients.

Conclusions

Specific effects can be related to biofeedback content: when muscular-based information is used, a more direct effect on lower limb spasticity and muscle activity is evidenced. In a similar manner, when biofeedback treatment is based on joint torque data, a higher patient compliance effect in terms of force exerted is achieved. Subjects who underwent EMGb seemed to be more motivated than those treated with Rb.

The use of biofeedback for gait retraining: A mapping review

BACKGROUND

Biofeedback seems to be a promising tool to improve gait outcomes for both healthy individuals and patient groups. However, due to differences in study designs and outcome measurements, it remains uncertain how different forms of feedback affect gait outcomes. Therefore, the aim of this study is to review primary biomechanical literature which has used biofeedback to alter gait-related outcomes in human participants.

METHODS

Medline, Cinahl, Cochrane, SPORTDiscus and Pubmed were searched from inception to December 2017 using various keywords and the following MeSHterms: biofeedback, feedback, gait, walking and running. From the included studies, sixteen different study characteristics were extracted.

FINDINGS

In this mapping review 173 studies were included. The most common feedback mode used was visual feedback (42%, n = 73) and the majority fed-back kinematic parameters (36%, n = 62). The design of the studies was poor: only 8% (n = 13) of the studies had both a control group and a retention test; 69% (n = 120) of the studies had neither. A retention test after 6 months was performed in 3% (n = 5) of the studies, feedback was faded in 9% (n = 15) and feedback was given in the field rather than the laboratory in 4% (n = 8) of the studies.

INTERPRETATION

Further work on biofeedback and gait should focus on the direct comparison between different modes of feedback or feedback parameters, along with better designed and field based studies.

Effectiveness and Superiority of Rehabilitative Treatments in Enhancing Motor Recovery Within 6 Months Poststroke: A Systemic Review

OBJECTIVE

To investigate the effects of various rehabilitative interventions aimed at enhancing poststroke motor recovery by assessing their effectiveness when compared with no treatment or placebo and their superiority when compared with conventional training program (CTP).

DATA SOURCE

A literature search was based on 19 Cochrane reviews and 26 other reviews. We also updated the searches in PubMed up to September 30, 2017.

STUDY SELECTION

Randomized controlled trials associated with 18 experimented training programs (ETP) were included if they evaluated the effects of the programs on either upper extremity (UE) or lower extremity (LE) motor recovery among adults within 6 months poststroke; included ≥10 participants in each arm; and had an intervention duration of ≥10 consecutive weekdays.

DATA EXTRACTION

Four reviewers evaluated the eligibility and quality of literature. Methodological quality was assessed using the PEDro scale.

DATA SYNTHESIS

Among the 178 included studies, 129 including 7450 participants were analyzed in this meta-analysis. Six ETPs were significantly effective in enhancing UE motor recovery, with the standard mean differences (SMDs) and 95% confidence intervals outlined as follow: constraint-induced movement therapy (0.82, 0.45-1.19), electrostimulation (ES)-motor (0.42, 0.22-0.63), mirror therapy (0.71, 0.22-1.20), mixed approach (0.21, 0.01-0.41), robot-assisted training (0.51, 0.22-0.80), and task-oriented training (0.57, 0.16-0.99). Six ETPs were significantly effective in enhancing LE motor recovery: body-weight-supported treadmill training (0.27, 0.01-0.52), caregiver-mediated training (0.64, 0.20-1.08), ES-motor (0.55, 0.27-0.83), mixed approach (0.35, 0.15-0.54), mirror therapy (0.56, 0.13-1.00), and virtual reality (0.60, 0.15-1.05). However, compared with CTPs, almost none of the ETPs exhibited significant SMDs for superiority.

CONCLUSIONS

Certain experimented interventions were effective in enhancing poststroke motor recovery, but little evidence supported the superiority of experimented interventions over conventional rehabilitation.

The Efficacy of Gait Training Using a Body Weight Support Treadmill and Visual Biofeedback in Patients with Subacute Stroke: A Randomized Controlled Trial

BACKGROUND

This study was designed to determine whether or not gait training based on the use of treadmill with visual biofeedback and body weight support (BWS) would produce better effects in patients with subacute stroke compared to BWS treadmill training with no visual biofeedback.

MATERIALS AND METHODS

30 patients with subacute stroke were randomly assigned to do body weight supported treadmill training with visual biofeedback (BB group) or BWS treadmill training without visual biofeedback. Their gait was assessed with a 3D system (spatiotemporal gait parameters and symmetry index) and by means of 2-minute walk test (2 MWT), 10-metre walk test (10 MWT), and Timed Up & Go test. Subjects in both groups participated in 15 treadmill training sessions (30 minutes each).

RESULTS

The participants from both groups achieved a statistically significant improvement in spatiotemporal gait parameters, walking speed, endurance, and mobility. The average change in the BB group after the end of the programme did not differ significantly compared to the change in the control group. The change in the symmetry index value of stance phase in the BB group was 0.03 (0.02) and in the control group was 0.02 (0.02). The difference was not statistically significant (p = 0.902). The statistically significantly higher improvement in the BB group was found in the range of walking speed (p = 0.003) and endurance (p = 0.012), but the difference between groups was of low clinical significance.

CONCLUSIONS

The findings do not confirm that BWS treadmill training with the function of visual biofeedback leads to significantly greater improvement in gait compared to BWS treadmill training with no visual biofeedback at an early stage after stroke. This study was registered at ClinicalTrials.gov, ID: ACTRN12616001283460.

Effects of real-time gait biofeedback on paretic propulsion and gait biomechanics in individuals post-stroke

Objectives Gait training interventions that target paretic propulsion induce improvements in walking speed and function in individuals post-stroke. Previously, we demonstrated that able-bodied individuals increase propulsion unilaterally when provided real-time biofeedback targeting anterior ground reaction forces (AGRF). The purpose of this study was to, for the first time, investigate short-term effects of real-time AGRF gait biofeedback training on post-stroke gait. Methods Nine individuals with post-stroke hemiparesis (6 females, age = 54 ± 12.4 years 39.2 ± 24.4 months post-stroke) completed three 6-minute training bouts on an instrumented treadmill. During training, visual and auditory biofeedback were provided to increase paretic AGRF during terminal stance. Gait biomechanics were evaluated before training, and during retention tests conducted 2, 15, and 30 minutes post-training. Primary dependent variables were paretic and non-paretic peak AGRF; secondary variables included paretic and non-paretic peak trailing limb angle, plantarflexor moment, and step length. In addition to evaluating the effects of biofeedback training on these dependent variables, we compared effects of a 6-minute biofeedback training bout to a non-biofeedback control condition. Results Compared to pre-training, significantly greater paretic peak AGRFs were generated during the 2, 15, and 30-minute retention tests conducted after the 18-minute biofeedback training session. Biofeedback training induced no significant effects on the non-paretic leg. Comparison of a 6-minute biofeedback training bout with a speed-matched control bout without biofeedback demonstrated a main effect for training type, with greater peak AGRF generation during biofeedback. Discussion Our results suggest that AGRF biofeedback may be a feasible and promising gait training strategy to target propulsive deficits in individuals post-stroke.