Biofeedback Strategies Research Articles

Combining inertial-based ergonomic assessment with biofeedback for posture correction: A narrative review

Work-related musculoskeletal disorders (WRMSDs) are the most reported work-related health problem in the European Union, representing an economic burden equivalent to 2% of its gross domestic product. Awkward postures are one of the main risk factors. Several postural assessment tools try to identify ergonomic exposure factors for evaluating WRMSD risk, yet these are commonly based on observation. Replacing observations with objective measurements can bring more accuracy and reproducibility to this analysis; hence, a direct measurement approach for the assessment is desired. This review looks for two-fold solutions, able to not only monitor workers’ posture using inertial sensors but also to return that information to the user, in a biofeedback loop. It presents systems for posture risk assessment, regarding ergonomic methods, sensors’ and actuators’ characteristics, and validation protocols. In particular, this review advances previous manuscripts by exploring the literature regarding different biofeedback strategies and ways to encode meaningful information in the cues, i.e., able to deliver intuitive ergonomic guidance so that the user becomes aware and changes into a more neutral posture. The combination of inertial sensors and vibrotactile motors stood out, due to its effectiveness in reducing postural risk. Directional feedback to guide users’ segments individually was found to be a promising strategy, although its validation is still limited. The results of the reviewed manuscripts pointed out the relevant practices, potentialities, and limitations of the existing solutions, allowing the identification of future challenges.

The Development of a Wearable Biofeedback System to Elicit Temporal Gait Asymmetry using Rhythmic Auditory Stimulation and an Assessment of Immediate Effects.

Temporal gait asymmetry (TGA) is commonly observed in individuals facing mobility challenges. Rhythmic auditory stimulation (RAS) can improve temporal gait parameters by promoting synchronization with external cues. While biofeedback for gait training, providing real-time feedback based on specific gait parameters measured, has been proven to successfully elicit changes in gait patterns, RAS-based biofeedback as a treatment for TGA has not been explored. In this study, a wearable RAS-based biofeedback gait training system was developed to measure temporal gait symmetry in real time and deliver RAS accordingly. Three different RAS-based biofeedback strategies were compared: open- and closed-loop RAS at constant and variable target levels. The main objective was to assess the ability of the system to induce TGA with able-bodied (AB) participants and evaluate and compare each strategy. With all three strategies, temporal symmetry was significantly altered compared to the baseline, with the closed-loop strategy yielding the most significant changes when comparing at different target levels. Speed and cadence remained largely unchanged during RAS-based biofeedback gait training. Setting the metronome to a target beyond the intended target may potentially bring the individual closer to their symmetry target. These findings hold promise for developing personalized and effective gait training interventions to address TGA in patient populations with mobility limitations using RAS.

The Effect of Varied Microperimetric Biofeedback Training in Central Vision Loss: A Randomized Trial.

This investigation reports for the first time the effects of different microperimetric biofeedback strategies in visually impaired subjects with central field loss. To evaluate the effects of two MP-3 micro-perimeter biofeedback strategies on the visual performance of subjects with central vision loss. Moreover, changes between the groups were compared to provide indications of practice with biofeedback stimulation in subjects with central vision loss. Using simple randomization, 19 participants were trained according to two different biofeedback stimulation approaches using the MP-3 microperimeter. Patients were assigned to two different groups: subjects trained for 2 days a week (Group A) and 3 days a week (Group B). The patients in each group were randomized to perform a total of 10 or 15 sessions. Fixation stability increased from 4.5°2 (± 2.8) to 2.3°2 (± 2.2) and from 8.2°2 (± 6.9) to 1.4°2 (± 1) after 2 and 3 weekly biofeedback training sessions, respectively (P < .05). Biofeedback training induced a significant improvement of 40.7% and 29.4% in reading speed for groups A and B, respectively (P < .05). A comparison of two weekly biofeedback training sessions with three weekly biofeedback sessions demonstrated greater fixation stability in Group B (P < .05). This study conclude that a biofeedback intervention is effective in enhancing oculomotor control in patients with central vision loss. In our study, a more intensive biofeedback strategy seemed to produce significantly better results in terms of functional vision parameters.

Motor control complexity can be dynamically simplified during gait pattern exploration using motor control-based biofeedback.

Understanding how the central nervous system coordinates diverse motor outputs has been a topic of extensive investigation. Although it is generally accepted that a small set of synergies underlies many common activities, such as walking, whether synergies are equally robust across a broader array of gait patterns or can be flexibly modified remains unclear. Here, we evaluated the extent to which synergies changed as nondisabled adults (n = 14) explored gait patterns using custom biofeedback. Secondarily, we used Bayesian additive regression trees to identify factors that were associated with synergy modulation. Participants explored 41.1 ± 8.0 gait patterns using biofeedback, during which synergy recruitment changed depending on the type and magnitude of gait pattern modification. Specifically, a consistent set of synergies was recruited to accommodate small deviations from baseline, but additional synergies emerged for larger gait changes. Synergy complexity was similarly modulated; complexity decreased for 82.6% of the attempted gait patterns, but distal gait mechanics were strongly associated with these changes. In particular, greater ankle dorsiflexion moments and knee flexion through stance, as well as greater knee extension moments at initial contact, corresponded to a reduction in synergy complexity. Taken together, these results suggest that the central nervous system preferentially adopts a low-dimensional, largely invariant control strategy but can modify that strategy to produce diverse gait patterns. Beyond improving understanding of how synergies are recruited during gait, study outcomes may also help identify parameters that can be targeted with interventions to alter synergies and improve motor control after neurological injury.NEW & NOTEWORTHY We used a motor control-based biofeedback system and machine learning to characterize the extent to which nondisabled adults can modulate synergies during gait pattern exploration. Results revealed that a small library of synergies underlies an array of gait patterns but that recruitment from this library changes as a function of the imposed biomechanical constraints. Our findings enhance understanding of the neural control of gait and may inform biofeedback strategies to improve synergy recruitment after neurological injury.

Dynamic assessment of the upper extremity: a review of available and emerging technologies.

The purpose of this review article is to provide an update on the realm of emerging technology available for the assessment of dynamic functional movement of the hand and upper limb. A critical overview of the literature and a conceptual framework for use of such technologies is proposed. The framework explores three broad purpose categories including customization of care, functional surveillance and interventions through biofeedback strategies. State-of-the-art technologies are described, from basic activity monitors to feedback-enabled robotic gloves, along with exemplar trials and clinical applications. The future of technologies innovation in hand pathology is proposed in the context of the current obstacles and opportunities for hand surgeons and therapists.

A Single-Session Eye Movement Desensitization and Reprocessing (EMDR) Therapy Reduces Anxiety and Improves Self-confidence in Athletes with Post-traumatic Stress Associated with Injury

Background: Stress and anxiety related to post-injury trauma in athletes is a latent problem in sport. The use of eye movement desensitization and reprocessing (EMDR) allows sports psychologists to intervene with their athletes more effectively to help them into their recovery and achieve peak sport performance. Objectives: Analyze the EMDR therapy effect in the psychophysiological responses of four athletes with stress related to a traumatic event during sports practice. Methods: Four athletes (22.25 ± 1.71 years; 11.5 ± 2.65 years of experience) participated an idiographic single-case, multiple-probe study. The Sport Psychology Department of the institution approved the study for its application, which also followed the statement of the declaration of Helsinki. The participants had been medically cleared to practice their sport after sustaining a severe injury, but they expressed significant difficulty in performing optimally yet. The Competitive State Anxiety Inventory-2RD was applied to measure the anxiety and self-confidence levels before, after and two weeks later EMDR therapy intervention. Eye movement desensitization and reprocessing standard protocol therapy was carried out to identify the dysfunctional memories to be reprocessed, address the abnormal behaviors as trauma consequences, and develop the behavioral changes to manage the trauma. Heart rate variability parameters used as biofeedback were monitored during the EMDR protocol to associate with moments of stress and relief. Data analysis was performed using the smallest worthwhile change (SWC) of Hopkins to compare the results in the different moments of the protocol and study. Results: All four athletes reported likely and most likely beneficial changes (according to the SWC) in their levels of anxiety and self-confidence after the intervention with the EMRD therapy as well as at two weeks afterward. Heart rate variability (HRV) parameters linked with parasympathetic activity were reduced and the sympathetic parameters increased their levels when the intervention protocol induced stressor memories, observing an opposite behavior when EMDR phases let the athlete be relaxed or getting relief. Conclusions: Eye movement desensitization and reprocessing is a therapy is effective to manage a sport injury related psychologic trauma. Furthermore both, LnRMSSD and LnSS parameters of the HRV can be used as a biofeedback strategy for a better efficacy of EMDR-based treatment.

Towards Posture and Gait Evaluation through Wearable-Based Biofeedback Technologies

In medicine and sport science, postural evaluation is an essential part of gait and posture correction. There are various instruments for quantifying the postural system’s efficiency and determining postural stability which are considered state-of-the-art. However, such systems present many limitations related to accessibility, economic cost, size, intrusiveness, usability, and time-consuming set-up. To mitigate these limitations, this project aims to verify how wearable devices can be assembled and employed to provide feedback to human subjects for gait and posture improvement, which could be applied for sports performance or motor impairment rehabilitation (from neurodegenerative diseases, aging, or injuries). The project is divided into three parts: the first part provides experimental protocols for studying action anticipation and related processes involved in controlling posture and gait based on state-of-the-art instrumentation. The second part provides a biofeedback strategy for these measures concerning the design of a low-cost wearable system. Finally, the third provides algorithmic processing of the biofeedback to customize the feedback based on performance conditions, including individual variability. Here, we provide a detailed experimental design that distinguishes significant postural indicators through a conjunct architecture that integrates state-of-the-art postural and gait control instrumentation and a data collection and analysis framework based on low-cost devices and freely accessible machine learning techniques. Preliminary results on 12 subjects showed that the proposed methodology accurately recognized the phases of the defined motor tasks (i.e., rotate, in position, APAs, drop, and recover) with overall F1-scores of 89.6% and 92.4%, respectively, concerning subject-independent and subject-dependent testing setups.

Utility of Gait Biofeedback Training to Improve Walking Biomechanics in Patients With Chronic Ankle Instability: A Critically Appraised Topic.

Chronic ankle instability (CAI) is a condition that involves feelings of the ankle "giving way," pain, and decreased self-reported function. Individuals with CAI often demonstrate persistent biomechanical impairments during gait that are associated with repetitive lateral ankle sprains (LAS) and the development of early onset ankle posttraumatic osteoarthritis (OA). Traditional rehabilitation strategies have not successfully improved these reported aberrant gait biomechanics; thus, traditional rehabilitation may not effectively reduce the risk of recurrent LAS and ankle OA among individuals with CAI. Conversely, targeted gait training with biofeedback may be effective at decreasing the risk of recurring LAS and ankle OA if these rehabilitation strategies can promote individuals with CAI to develop a gait strategy that protects against subsequent LAS and ankle OA. Can targeted gait biofeedback interventions cause individuals with CAI to implement a walking gait pattern that is not associated with recurrent LAS and ankle OA? Five studies assessed gait biofeedback interventions targeting plantar pressure and/or ankle kinematics involving visual biofeedback (n = 3), auditory biofeedback (n = 1), and haptic biofeedback (n = 1). Plantar pressure was medially shifted during a single session while receiving biofeedback (n = 2), immediately after biofeedback (n = 1), and 5 minutes after receiving biofeedback (n = 1) in 3 studies. One study demonstrated reduced ankle inversion after 8 sessions of biofeedback training. One study did not substantially improve plantar pressure while receiving visual feedback. Targeted gait training strategies appear effective in acutely altering gait biomechanics in individuals with CAI while receiving, and immediately after, biofeedback has been removed. Long-term outcomes are not currently established for gait training strategies in those with CAI. Limited evidence (grade B) suggests that targeted gait biofeedback strategies can alter specific CAI gait biomechanics to a strategy not associated with recurrent LAS, and ankle OA immediately, and after, multiple sessions of gait training.

Reinforcement Learning-Based Adaptive Biofeedback Engine for Overground Walking Speed Training

Wearable biofeedback systems (WBS) have been proposed to aid physical rehabilitation of individuals with motor impairments. Due to significant inter- and intra-individual differences, the effectiveness of a given biofeedback strategy may vary for different users and across therapeutic sessions, as a patient’s functional recovery progresses. To date, only a paucity of research has investigated the use of biofeedback strategies that can self-adapt based on the user’s response. This letter introduces a novel reinforcement learning with fuzzy logic biofeedback engine (RLFLE) for personalized overground walking speed training. The method leverages reinforcement learning and a fuzzy inference strategy to continuously modulate underfoot vibrotactile stimuli that encourage users to achieve a target walking speed. This stimulation strategy also enables the determination of a user’s maximum steady-state walking speed during a gait training session overground. The RLFLE was implemented in a custom-engineered WBS and validated against two simpler biofeedback strategies during walking tests with healthy adults. Participants showed lower walking speed errors when training with the RLFLE. Additionally, results indicate that the new method is more effective in determining an individual’s maximum steady-state walking speed. Given the importance of walking speed as an indicator of health status and as an essential outcome of exercise-based interventions, these results show promise for implementation in future technology-enhanced gait rehabilitation protocols.

Distraction Classification During Target Tracking Tasks Involving Target and Cursor Flickering Using EEGNet.

Keeping patients from being distracted while performing motor rehabilitation is important. An EEG-based biofeedback strategy has been introduced to help encourage participants to focus their attention on rehabilitation tasks. Here, we suggest a BCI-based monitoring method using a flickering cursor and target that can evoke a steady-state visually evoked potential (SSVEP) using the fact that the SSVEP is modulated by a patient's attention. Fifteen healthy individuals performed a tracking task where the target and cursor flickered. There were two tracking sessions, one with and one without flickering stimuli, and each session had four conditions in which each had no distractor (non-D), a visual (vis-D) or cognitive distractor (cog-D), and both distractors (both-D). An EEGNet was trained as a classifier using only non-D and both-D conditions to classify whether it was distracted and validated with a leave-one-subject-out scheme. The results reveal that the proposed classifier demonstrates superior performance when using data from the task with the flickering stimuli compared to the case without the flickering stimuli. Furthermore, the observed classification likelihood was between those corresponding to the non-D and both-D when using the trained EEGNet. This suggests that the classifier trained for the two conditions could also be used to measure the level of distraction by windowing and averaging the outcomes. Therefore, the proposed method is advantageous because it can reveal a robust and continuous level of patient distraction. This facilitates its successful application to the rehabilitation systems that use computerized technology, such as virtual reality to encourage patient engagement.

A Single-Session Eye Movement Desensitization and Reprocessing (EMDR) Therapy Reduces Anxiety and Improves Self-confidence in Athletes with Post-traumatic Stress Associated with Injury

Background: Stress and anxiety related to post-injury trauma in athletes is a latent problem in sport. The use of eye movement desensitization and reprocessing (EMDR) allows sports psychologists to intervene with their athletes more effectively to help them into their recovery and achieve peak sport performance. Objectives: Analyze the EMDR therapy effect in the psychophysiological responses of four athletes with stress related to a traumatic event during sports practice. Methods: Four athletes (22.25 ± 1.71 years; 11.5 ± 2.65 years of experience) participated an idiographic single-case, multiple-probe study. The Sport Psychology Department of the institution approved the study for its application, which also followed the statement of the declaration of Helsinki. The participants had been medically cleared to practice their sport after sustaining a severe injury, but they expressed significant difficulty in performing optimally yet. The Competitive State Anxiety Inventory-2RD was applied to measure the anxiety and self-confidence levels before, after and two weeks later EMDR therapy intervention. Eye movement desensitization and reprocessing standard protocol therapy was carried out to identify the dysfunctional memories to be reprocessed, address the abnormal behaviors as trauma consequences, and develop the behavioral changes to manage the trauma. Heart rate variability parameters used as biofeedback were monitored during the EMDR protocol to associate with moments of stress and relief. Data analysis was performed using the smallest worthwhile change (SWC) of Hopkins to compare the results in the different moments of the protocol and study. Results: All four athletes reported likely and most likely beneficial changes (according to the SWC) in their levels of anxiety and self-confidence after the intervention with the EMRD therapy as well as at two weeks afterward. Heart rate variability (HRV) parameters linked with parasympathetic activity were reduced and the sympathetic parameters increased their levels when the intervention protocol induced stressor memories, observing an opposite behavior when EMDR phases let the athlete be relaxed or getting relief. Conclusions: Eye movement desensitization and reprocessing is a therapy is effective to manage a sport injury related psychologic trauma. Furthermore both, LnRMSSD and LnSS parameters of the HRV can be used as a biofeedback strategy for a better efficacy of EMDR-based treatment.

Effects of Visual Biofeedback on Symmetrical Movements During Bridge Exercise With Sling.

Asymmetrical movements of trunk and lower-extremity are common during the bridge exercise on the unstable condition. However, no studies have investigated whether visual biofeedback of pressing pressure on the unstable surface changes muscle activation patterns of trunk and hip extensors and pelvic rotation during the bridge exercise. To investigate how visual biofeedback of pressing pressure influences symmetrical activity of lumbar and hip extensor and pelvic rotation. Cross-sectional study. Laboratory. Twenty healthy males participated in this study. The participants performed 2 versions of the bridge exercise: the standard bridge exercise and the bridge exercise with visual biofeedback using amount of pressing pressure on the sling. Surface electromyography was used to measure the symmetry (ie, the difference between dominant and nondominant sides) of muscle activation in the bilateral erector spinae, gluteus maximus, and hamstring muscles, and motion sensors were used to assess pelvic rotation. Symmetry of pressing pressure was measured using a tension meter. The differences between the dominant and nondominant pressing pressures and differences between the electromyography activity of the dominant and nondominant erector spinae, gluteus maximus, and hamstring were significantly smaller during the bridge exercise with visual biofeedback than during the standard bridge exercise (P < .05). In addition, there was significantly less pelvic rotation during the bridge exercise with visual biofeedback than during the standard bridge exercise (P < .05). The present findings suggest that visual biofeedback strategy may be a useful method for enhancing the symmetrical activation of the erector spinae, gluteus maximus, and hamstring and for reducing pelvic rotation during the bridge exercise on the unstable surface.

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.

Smart Vest for Real-Time Postural Biofeedback and Ergonomic Risk Assessment

Work-related musculoskeletal disorders (WRMSDs) are a serious worldwide health concern, that can result in the worker’s permanent disability and an economic burden of up to 2% of the Gross Domestic Product (GDP). This paper presents the design and development of an innovative smart garment for real-time ergonomic risk assessment. It aims to empower operators with posture awareness and provide objective data to ergonomists. The system is based on inertial sensors and implements a biofeedback strategy that uses haptic stimulus to warn the user about hazard postures, enabling more ergonomic postures. To allow an easy data analysis, a graphical interface was developed in MATLAB. This framework was validated with 5 subjects, in a simulated scenario with 5 tasks that included a collaborative robot arm. The results showed that providing real-time biofeedback to the subject improves posture awareness, and has a significant impact on reducing the ergonomic risk, with reductions of up to 39.8% of the time spent in hazard postures. The wearable technology and developed methodologies are a promising tool to complement the ergonomist diagnoses of hazard tasks and workspaces and to reduce the risk of musculoskeletal disorders.

Biofeedback strategy and reduction of foot pressure in diabetic patient with neuropathy: Benefit of connected insoles FEETME: A preliminary study

Plantar pressure reduction is mandatory to prevent foot ulceration in patients with diabetic peripheral neuropathy. Biofeedback strategy is a promising approach to reduce pressure at-risk zone and to lastingly train patient in this specific task. FeetMe One is a novel connected in-shoe device measuring plantar pressure and gait parameters. The objective was to evaluate the biofeedback method to reduce the plantar pressure at-risk zone as a clinical routine and monitored by FEETME insoles. The impact of the new walking was quantitatively analyzed by the plantar pressure map provided by these insoles. Wireless pressure-sensitive insoles (FeetMe One) calculate plantar pressure map and multiple gait patterns. We included 11 patients. In the first part, subjects walked without instruction to collect baseline trial (approximately 20 steps). After the at-risk zone identification, all subjects trained to reduce the max peak pressure on the basis of pressure map analysis. The patient was considered to have learned a new walking strategy as soon as the peak plantar pressure under the previously defined at-risk zone was within a range of 40–80% of baseline plantar pressure in 70% of the totality of steps and during three consecutive walking sequences. The retention tests were immediately performed after the learning and after 2 and 6 weeks to determine if motor pattern changes could occur over a long period. After the learning session, 8 patients succeeded in training a new walking strategy (9 fore foot and 2 heel). The max pressure threshold was lower than 80% for these patients. Five patients over 6 (2 lost in follow-up) persisted over 2 weeks to walk without plantar pressure overloaded in any specific area. The retention test after 6 weeks showed that the foot off-loading was still reduced without inducing a new at-risk zone. However, only 50% of steps were lower than the max pressure threshold for all patients. This study should be performed for a larger number of patients and a longer retention but these preliminary results are encouraging.

Visual Recovery after Primary Retinal Detachment Surgery: Biofeedback Rehabilitative Strategy.

Purpose. To evaluate possible speeding up recovery time after retinal detachment (RD) surgery using biofeedback strategy. Methods. A total of 52 eyes were selected. After surgery, patients were divided into two groups: group A, including patients submitted to biofeedback with MP-1 strategy; group B, patients who received common care strategy. Biofeedback strategy was started 15 days after the suspension of cycloplegic eye drops in buckling procedure or after silicone oil removal in the vitrectomized eyes. Controls were scheduled at baseline and 6, 12, and 18 weeks. Results. At baseline, there was no significant difference in BCVA between groups (P = 0.4230). At the end of biofeedback treatment (WK 6) BCVA of group A was significantly better (P < 0.001) than group B and BCVA was still better in group A than group B at WK 12 (P = 0.028) and at WK 18 (P = 0.041). Conclusions. Visual recovery after RD surgery is still unclear, and it does not depend on entity of the RD. Our data demonstrate that in biofeedback group there was a significant recovery in visual performances that still remains evident after 3 months from the baseline.

Factors Associated With Efficacy of Nurse-led Bowel Training of Patients With Chronic Constipation

It is not clear whether nurse-led bowel training (NBT), an individually tailored biofeedback strategy designed to improve the physiological process of defecation by operant conditioning and trial and error learning, is effective for patients with chronic constipation. We assessed the ability of NBT to reduce symptoms and increase quality of life in patients with constipation at a large tertiary medical center. We performed a retrospective analysis of data from 347 patients (median age, 50 years) who underwent a median 3 sessions of NBT for chronic constipation from January 2011 through December 2013 at St Marks Hospital in the United Kingdom. The NBT comprised a combination of sensory retraining, pelvic floor conditioning, and advice on diet and toileting behavior. Data on patient demographics (age, sex, type of constipation) were collected alongside their assessments of constipation, which were based on Patient Assessment of Constipation Quality of Life (PAC-QoL) and patient satisfaction scores. We performed binary logistic regression analysis. Each variable was tested first at the univariate level; those with significance (P < .10) were included in a multivariate model. At the end of NBT, 62.5% of the patients (217/347) reported reduced symptoms, and 40.2% of the patients (41/102) reported a reduction of at least 1 point on the PAC-QoL score. The mean PAC-QoL scores before and after NBT were 2.42 and 1.41, respectively (P = .001). Multivariate analysis demonstrated that increasing age (odds ratio [OR], 1.71; 95% confidence interval [CI], 1.02-2.87; P = .042), greater number of sessions (OR, 4.14; 95% CI, 2.09-8.20; P < .001), and non-irrigation (OR, 4.39; 95% CI, 1.89-10.19; P = .001) were independent predictors of patient satisfaction. Data collected immediately after patients with chronic constipation received NBT indicate that it is an effective treatment for most patients. Older patients with dyssynergic defecation benefit most from at least 4 sessions.

Biofeedback stimulation in patients with age-related macular degeneration: comparison between 2 different methods

ObjectiveTo evaluate changes in patient’s visual performance after rehabilitation training with 2 different biofeedback training programs offered by the MP-1 microperimeter. Spontaneous retinal location of preferred retinal loci (PRLs) and fixation stability are not always optimal for best visual performances. MP-1 microperimeter biofeedback techniques have been suggested as modalities for training for better fixation stability and to find a better location of the new PRL in a more useful area of the retina in nonoptimal cases. The MP-1 microperimeter offers different biofeedback strategies, such as acoustic biofeedback and structured light stimulus plus acoustic biofeedback. DesignRetrospective study. ParticipantsThirty subjects affected by age-related macular degeneration with absolute central scotoma. MethodsA standard protocol of examination before and after visual rehabilitation training was performed on all study subjects. Assessment included demographics data, visual acuity, fixation stability, retinal sensitivity, and reading speed. Rehabilitation training was performed with standard and structured stimulus biofeedback. The whole sample was divided into 2 groups of 15 patients attending the 2 different stimulation training biofeedback. ResultsMean reading speed was found to be significantly increased for both groups (p < 0.05 and p < 0.01). Also, a statistically significant improvement of fixation stability was registered for both groups (p < 0.01). Only patients trained with the flickering pattern biofeedback stimulation increased retinal sensitivity (p < 0.01). ConclusionsBoth regular biofeedback and flickering pattern biofeedback training seem to improve visual functions. More benefits seem to be accrued, however, with flickering pattern biofeedback training.

Evaluation of robot-assisted gait training using integrated biofeedback in neurologic disorders

BackgroundNeurological disorders lead to walking disabilities, which are often treated using robot-assisted gait training (RAGT) devices such as the driven gait-orthosis Lokomat. A novel integrated biofeedback system was developed to facilitate therapeutically desirable activities during walking. The aim of this study was to evaluate the feasibility to detect changes during RAGT by using this novel biofeedback approach in a clinical setting for patients with central neurological disorders. Methods84 subjects (50 men and 34 women, mean age of 58±13years) were followed over 8 RAGT sessions. Outcome measures were biofeedback values as weighted averages of torques measured in the joint drives and independent parameters such as guidance force, walking speed, patient coefficient, session duration, time between sessions and total treatment time. ResultsJoint segmented analysis showed significant trends for decreasing hip flexion activity (p≤.003) and increasing knee extension activity (p≤.001) during RAGT sessions with an intercorrelation of r=−.43 (p≤.001). Further associations among independent variables were not statistically significant. ConclusionThis is the first study that evaluates the Lokomat integrated biofeedback system in different neurological disorders in a clinical setting. Results suggest that this novel biofeedback approach used in this study is not able to detect progress during RAGT. These findings should be taken into account when refining existing or developing new biofeedback strategies in RAGT relating to appropriate systems to evaluate progress and support therapist feedback in clinical settings.

Chronic prostatitis during puberty

To investigate the features of chronic prostatitis (CP) during puberty and the effects of biofeedback on young males with this disease. In all, 40 patients were divided into two groups; group 1 included 25 pubertal patients with CP (mean age 16.5 years, sd 1.1) and group 2 was a control group including 15 patients (mean age 16.2 years, sd 1.2) with a normal lower urinary tract. National Institute of Health-Chronic Prostatitis Symptom Index (NIH-CPSI) scores (three parts) were assessed individually in both groups. Expressed prostatic secretions and urine samples after prostate massage from group 1 were cultured to determine whether patients were infected with bacteria, and group 1 was categorized into various NIH types. Each patients in the two groups underwent urodynamics and group 1 were treated with biofeedback. In group 1, there were one, three and 21 patients with type II, IIIA and IIIB prostatitis. The incidence of staccato voiding and detrusor-sphincter dyssynergia (DSD), and the maximum urinary flow rate (Qmax), postvoid residual urine volume (PVR), maximum detrusor pressure (Pdetmax) and maximum urethral closure pressure (MUCP) between the groups were significantly different (P < 0.05). The total NIH-CPSI scores and all the subdomains between the groups before biofeedback were significantly different (P < 0.001). In group 1 the difference in NIH-CPSI scores and Qmax before and after biofeedback was significant (P < 0.05). The main type of CP during puberty is IIIB; the dominating symptom is a voiding disorder. The impact on life and psychological effects are substantial. Pubertal boys with CP have pelvic floor dysfunction and several abnormal urodynamic values, i.e. staccato voiding, DSD, decreasing Qmax, and increasing Pdetmax and MUCP. The effect of biofeedback strategies for treating pubertal CP is satisfactory.