Knee Biofeedback Rehabilitation Interface for Game-based Home Therapy (KneeBRIGHT) in Patients with Knee Osteoarthritis: A Protocol for Evaluating the KneeBRIGHT System via Randomized,Controlled Clinical Trial

Abstract

Background:

Patients with knee osteoarthritis who seek physical therapy interventions often struggle with compliance to prescribed exercise regimens, resulting in reduced benefits of physical therapy programs. More engaging and technology-enabled interventions incorporating real-time biofeedback and gamification have shown promise in improving exercise adherence and outcomes.

Objective:

The subject research study aims to evaluate whether the KneeBRIGHT system, an electromyographic biofeedback-based video gaming system, improves exercise adherence and functional outcomes compared to standard physical therapy. We hypothesize that the incorporation of a real-time biofeedback and gamification system will be more engaging and fun, and in turn, will increase exercise adherence and lead to better clinical outcomes.

Methods:

This is a prospective, single-blinded, randomized control trial conducted at a single academic center in collaboration with 5 local physical therapy clinics. Sixty patients between 40 and 75 years old with radiographically diagnosed knee osteoarthritis will be randomized to an 8-week structured rehabilitation program that includes a combination of both clinic and home exercise sessions with or without the KneeBRIGHT system. OUTCOMES: The primary outcome measured will be pre-to-post changes in patient reported outcomes (KOOS), with secondary outcomes measured in functional performance tests, protocol adherence, and technology acceptance assessments.

Trial Registration:

ClinicalTrials.gov, NCT06090097. URL: https://clinicaltrials.gov/study/NCT06090097.

Keywords

knee osteoarthritis physical therapy and rehabilitation telerehabilitation biofeedback exergaming

Introduction

Arthritis is among the leading causes of disability around the world.¹ Osteoarthritis (OA), the most prevalent form of arthritis, carries an estimated economic burden of over $65 billion annually in the US and likely accounts for most of the 180.9 million workdays lost due to arthritis between 2013 and 2015.^2,3 A combination of chronic structural degeneration, mechanical stress, and joint inflammation causes joint stiffness and pain that leaves many OA patients with reduced physical activity and disability. OA is an incurable disease, and unfortunately, the negative economic and quality of life impacts of OA are only expected to increase in coming years.⁴ Knee OA specifically accounts for most cases of OA globally and thus is a major target for clinicians.^5,6 Physical therapy (PT) and weight loss are the frontline, non-medical interventions that are employed when treating OA. Pharmacological interventions include oral or topical NSAIDs, which subsequently progress to cortisone and hyaluronic acid injections. Patients who have persistent symptoms despite these treatments eventually seek a partial or total knee replacement.⁷

The effectiveness of PT in alleviating OA symptoms has been well established.^8,9 PT has demonstrated significant benefits in reducing knee pain, improving physical function,¹⁰ and even rates of knee replacement surgery 1-year post-treatment when compared to a control.¹¹ While considerable research effort has focused on optimizing PT protocols themselves,^12,13 emerging technologies that supplement and enhance PT have shown promise. Among these is electromyographic biofeedback (EMG-BF), a tool that provides real-time muscle activity to a patient in an either visual or auditory form. EMG-BF has been shown to improve strength, reduce pain, and decrease fear of movement when complemented with PT exercises.^14,15

The primary limitation of PT interventions is that their benefits require patients to adhere to long-term exercise programs to maintain rehabilitation gains. These programs are typically established during supervised clinic visits, but the increasing costs in healthcare make such long-term supervised programs unrealistic for most patients. The expense of in-person clinic visits, along with the transportation challenges faced by elderly, underserved, and isolated patients, has made it crucial for patients to incorporate home exercise programs (HEP) to supplement in-clinic PT. However, HEPs are repetitive and boring by nature, lacking a component that keeps patients engaged and makes the program enjoyable.¹⁶ Patients must also overcome the initial physical and psychological discomfort of exercise, which is only compounded in an environment without the support and supervision of a therapist.¹⁷ Furthermore, almost half of participants with knee OA are noted to be inactive, another negative predictive behavioral trait in home exercise adherence.¹⁸ Because of these obstacles, the majority of patients fail to continue with their home exercise program^19-22 and miss out on the benefits of long-term PT for their knee OA.²³

An innovative solution to this issue is the gamification of exercise programs.²⁴ Various forms of exergaming in different patient populations have been shown to increase adherence to therapy regiments^25
-27 and, as a result, increase patient rehabilitation progress and performance.^28
-30 Using a combination of both gamification and EMG-BF together could provide an enjoyable, engaging, and novel modality that not only increases patient adherence, but also enhances the therapeutic effects for patients. The present study examines the ability of the KneeBRIGHT system, a combination of gamification and EMG-BF developed by Barron Associates, to increase adherence and performance in patients with knee OA.

A preliminary feasibility study suggested that there may be benefits to the KneeBRIGHT system compared to a conventional EMG-BF interface as patients using the KneeBRIGHT system were able to produce greater knee torque and achieve longer exercise duration.³¹ However, the study had limitations, including having only 19 participants and using the system once. This fulfilled what was desired to be investigated however, and a subsequent efficacy clinical trial was conducted. This trial found that patients had increased adherence in exercise sessions over a 10-week period, although no significant difference in performance outcomes was found.³² However, the study was limited in size with only 29 participants, which was due to the pandemic causing a low recruitment and high attrition rate.

Building upon the earlier studies, this efficacy clinical trial will aim to (1) develop commercial KneeBRIGHT hardware and software and refine upon the technology developed; (2) assess usability and technology acceptance by a wider range of users, including multiple physical therapists; (3) introduce adherence monitoring features which provide clinicians with key metrics of patient progress; and (4) compare functional outcomes between participants performing exercises with the KneeBRIGHT system and a control group performing standard PT.

Methods

Clinical Trial Design and Registration

This protocol describes a single-site clinical trial that will be a prospective, parallel, single-blinded (assessor) randomized control trial with an allocation ratio of 1:1 and a superiority framework led by the University of North Carolina at Chapel Hill (UNC) department of orthopaedics in collaboration with 5 physical therapy practice sites throughout the local community in North Carolina. Recruited patients will complete a series of baseline tests, then complete 8 weeks of physical therapy with or without the KneeBRIGHT system, then conclude with post testing consisting of the same tests done at baseline testing apart from additional surveys and interviews. The study is registered in clinicaltrials.gov (NCT06090097) and sponsored through a grant from the National Aging Institute (Grant number 5R44AG062069-05). The trial protocol, statistical analyses planned, and study results will be made accessible in clinicaltrials.gov. Study results will also be made accessible through publication. See Table 1 for a table with a broad overview of the study.

Table 1.

Broad Study Overview.

	Screening	Baseline testing	Randomization	Weeks 1-4	Weeks 5-8	Post testing follow up
Time point	−t₁	0	0	t₁	t₂	t₃
Enrollment
Eligibility screening	X
Informed consent	X
Randomization			X
Intervention or comparator
KneeBRIGHT participants			X
Standard physical therapy participants			X
Intervention
Clinic visits				2 per week	1 per week
Home sessions				1 per week	2 per week
Assessments
VAS pain survey		X				X
KOOS survey		X				X
Anthropomorphic metrics		X				X
Single and double leg balance		X				X
Squat		X				X
30 s sit-to-stand		X				X
6MWT		X				X
Isometric and Isokinetic strength tests		X				X
Patient activation survey						X
Ease of use scale survey						X^a
Technology acceptance model survey						X^a

Only completed by participants in the KneeBRIGHT intervention group.

Patient Population

The study aims to recruit a total of 60 patients who are (1) between 40 and 75 years of age, who have a (2) diagnosis of knee OA, and (3) walk without the use of an assistive device. Patients with sensory impairments that prevent interaction with the KneeBRIGHT gaming system and interface, who have other symptomatic disease in their lower extremity that interferes with the assessment of the knee(s), or who received a cortisone injection in the last 3 months or a hyaluronic acid injection in the last 6 months are excluded from the study. For a full list of inclusion and exclusion criteria, see Table 2.

Table 2.

KneeBRIGHT Study Inclusion and Exclusion Criteria.

Inclusion criteria	Exclusion criteria
Age 40-75 y	Psychiatric or cognitive impairment (e.g., dementia) that interferes with the ability to follow instruction or provide voluntary consent
Diagnosis of knee OA	Symptomatic spine, hip, ankle, or foot disease other than OA that would interfere with assessment of the knee.
Walking without an assistive device	Diagnosis of a neurologic chronic pain condition (e.g., fibromyalgia).
	Pregnancy or possibility of pregnancy. Please report if you are pregnant, plan to become pregnant, or unexpectedly become pregnant.
	Physical impairment that prohibits use of a laptop computer.
	Visual or auditory impairment that prohibits engagement with device’s video display.
	Cortisone or hyaluronic injection in knee within previous 3 or 6 mo, respectively.
	Lower extremity surgery within the previous year.

Recruitment, Screening, and Enrollment

Patient recruitment will be conducted through multiple avenues. Medical records will be reviewed from a monthly patient registry to identify eligible patients. Mass emails will be distributed periodically within the UNC system to employees that may qualify. Community outreach will be done through the advertisement of informational flyers at local wellness and community centers. In all cases of initial contact by the research team, it will be stated that participation is voluntary and that the research team is available to answer any question or concerns regarding the study.

Potential patients will also be recruited during their clinic visits, either by their direct care team or by follow-up by the research team. In clinic, treating physicians introduce the study as a possible treatment option, if appropriate, amongst other alternative treatment options that the treating physician may present. If interested, patients will be referred to the research team who would answer any questions that the patient has, along with explicitly stating that participation would limit pursuit of other knee OA treatment options for the period of the study.

Patients that pass the inclusion and exclusion criteria will have their most recent knee x-ray reviewed and classified by a licensed physician in the department of orthopaedics according to the Kellgren-Lawrence scale for radiographic classification of OA.^33,34 Patients scoring at least a 2 out of 4 on the scale will be eligible and only afterward will written informed consent be obtained. Lastly, patients will be scheduled for 8 weeks of physical therapy at 1 of 5 participating therapy clinics.

Baseline Testing

Following scheduling of their 8-week physical therapy regiment, participants will complete a baseline testing visit at the UNC Sports Medicine Institute. After signing an informed consent form approved by the Institutional Review Board (IRB), patients will complete a series of assessments conducted by a blinded assessor trained on baseline testing. The assessor is the only person involved with the study that will be blinded to the participant’s group assignment. Both groups will undergo the same objective tests, and the surveys post rehabilitation are completed by the patients themselves. The equipment that participants in both groups receive come in black bags that are identical and hold all the equipment needed for both groups. Equipment required for both groups is gathered by a study coordinator beforehand and given to the participant without the privy of the assessor.

First, anthropometrics including height and weight will be measured, and current level of knee pain will be assessed by visual analog scale (VAS). Then patients will complete a 5-minute warm-up on a stationary bike. Double- and single-leg balance and squat assessments will be subsequently performed using a pressure mat (Tekscan, Inc., Norwood, MA, USA) to evaluate center of pressure distance, center of pressure area, and percent weight bearing per limb. Patients then complete 1 trial of standing double leg balance with their hands placed on their hips for a maximum duration of 30 seconds. Next, they will complete one 15 second trial per limb of single leg balance with their hands on their hips, beginning with the involved limb. Balance trials are stopped prior to the maximum duration if the patient is unable to maintain their balance such that they take a step, remove their hands from their hips, or adjust their foot placement. Additionally, patients will perform 3 bodyweight squats, with instruction to have their feet positioned approximately shoulder-width apart, hold their arms in front of the body with elbows flexed and hands clasped, and to a depth of 90° of knee flexion or to a depth as tolerable given the patient population.

Testing continues with a maximum repetition sit-to-stand test off a 47 cm tall chair for 30 seconds.³⁵ It will be followed by a 6-minute walk in which the patients were informed that the purpose of the test is to measure how far they can walk in 6 minutes.³⁶ The distance is recorded by 2 timing gates (Dashr Systems, Omaha, NE, USA) set at 12 m apart. The timing gates record the number of laps completed in 6 minutes and the total walking distance for the 6-minute walk test is calculated by multiplying the number of laps by 12 m.

The objective testing will conclude with knee strength evaluation using an isokinetic dynamometer (HUMAC NORM, Computer Sports Medicine Inc., Stoughton, MA, USA) to measure peak torque. Patients will be seated in 85° hip flexion and 90° knee flexion in the dynamometer chair. They will complete one 5 second trial of maximal effort knee extension at 60° knee flexion, followed by 30 seconds of rest, and one 5 second trial of maximal effort knee flexion at 60° knee flexion. Both trials will be given clear instruction on the nature of the test and verbal encouragement during the repetition. Following 30 seconds rest, patients will complete 5 practice repetitions followed by 6 maximal effort test repetitions through the entire range of motion for knee extension and flexion at 120°/s. This procedure will be completed bilaterally beginning with the uninvolved limb followed by the involved limb.

Immediately following objective testing, patients will report their current knee pain using VAS again. The purpose of the participant reporting another VAS pain score after completing their objective testing is to assess how strenuous the baseline testing was for them and compare that experience to the testing they will do post rehabilitation. They will complete the Knee Injury Osteoarthritis Outcome Score (KOOS)³⁷ survey that addresses perceived knee function according to 5 subscales: symptoms, pain, function in activities of daily living, function in sport and recreation, and quality of life.

Randomization

Upon completion of baseline testing, participants will be randomized into 1 of the 2 study groups, a control group that is assigned to standard physical therapy without the KneeBRIGHT system and an intervention group that is assigned to complete the same PT regimen with the KneeBRIGHT system. Group allocation will be determined using stratified, restricted block randomization. Stratified by sex, each sex has 4 blocks of permuted cells that are pre-randomized to A = control and B = KneeBRIGHT. This is generated by a statistician using a centralized computer and the random allocation sequence is stored in a secure, password protected, HIPAA-compliant server. Members of the research team enrolling participants will only have access to the results of the randomization after participants have provided informed consent and undergone baseline testing.

Group specific protocols and responsibilities will be explained to each patient. All patients will be provided with a step-up platform, ankle weights, and a carrying bag; the intervention group patients will also receive extra equipment (laptop, EMG sensors, chargers, electrodes) specific to the KneeBRIGHT system. Finally, patients will be debriefed on prohibited concomitant care which includes cortisone and hyaluronic acid injections, starting other physical therapy programs, or making any sudden changes to their baseline level of physical activity. We also explained that use of NSAIDs or other pain medications in the setting of acute knee pain or inflammation was permissible.

Physical Therapy Intervention

Participants in both groups will receive 8 weeks of physical therapy following a defined PT protocol (see Supplemental Appendix A). The protocol will ensure evidence-based, tailored rehabilitation is delivered to all participants, while ensuring there is sufficient inclusion of quadriceps strengthening exercises. The only difference between groups will be the use of the KneeBRIGHT device, in clinic and at home, for participants randomized to the intervention group. The physical therapists participating will be licensed and trained in the protocol and use of the KneeBRIGHT device prior to the start of recruitment and refreshed on the device and protocol with a study coordinator for the first 2 clinic sessions of every new patient assigned. The study coordinator will be available for questions and direction as needed.

Physical therapy for all participants will consist of 12 clinic sessions, 2 per week for the initial 4 weeks and 1 per week for the final 4 weeks. During the first 4 weeks, participants will complete 1 additional exercise session at home and during the latter 4 weeks, participants will complete 2 additional exercise sessions at home for a total of 3 exercise sessions per week for the 8 weeks. Physical therapy will begin with an evaluation to identify impairments and functional limitations that would be addressed in typical physical therapy. Using the findings from the evaluation, the physical therapist will design a plan of care that focuses on quadriceps strength training but may include other interventions as indicated and allowed by the protocol.

Quadriceps strengthening exercises will be selected from a library of exercises that informed the design of the KneeBRIGHT game. Participants will complete at least 3 quadricep strengthening exercises per session at an intensity that results in muscle fatigue by the end of 3 sets of 8 to 10 repetitions. The KneeBRIGHT device will be used in clinic for those in the intervention group. At the conclusion of each clinic session, the physical therapist will update the KneeBRIGHT or standard home exercise program to reflect the current exercises and parameters. The physical therapist will instruct the participant in how many sessions to complete at home prior to their next clinic session. The physical therapist will record the details of the session in an electronic medical record. Protocol adherence by the patient for their clinic sessions will be monitored using these session notes written by the PTs. For home exercise sessions using KneeBRIGHT, surveys will be sent out using the Research Electronic Database Capture (REDCap) system³⁸ to collect information on what exercises were done, when they were done, and patient perceived difficulty of the exercise session. Survey responses from patients will be used to track protocol adherence for their home exercise sessions.

Post Rehabilitation Testing and Interviews

Upon completion of the 8-week PT regiment, patients will return to the UNC Sports Medicine Institute to repeat the baseline testing protocol (see Baseline Testing). Alongside the KOOS, patients will take an additional Patient Activation Survey³⁹ that assesses their knowledge and ability in managing their health (see Supplemental Appendix B). Patients that used the KneeBRIGHT system will be asked to complete 2 additional surveys, an Ease-of-Use Scale and a Technology Acceptance Model survey (see Supplemental Appendices C and D, respectively). The former aims to understand how difficult the KneeBRIGHT system was to use, and the latter examines how useful patients found the device to be and the feasibility of using it outside the study. Finally, patients in the investigational group will be interviewed and have their responses recorded regarding their experience using the KneeBRIGHT system (see Supplemental Appendix E). The interviews will be transcribed and have qualitative analysis conducted to identify specific patient themes relating to the investigational device based on their experiences in the trial. The qualitative analysis will take a hybrid inductive-deductive approach to find themes that allow for tangible changes to be made to the investigational device in preparation for market readiness.

KneeBRIGHT System Description

The KneeBRIGHT system consists of a computer and 2 surface EMG sensors placed on the vastus lateralis bilaterally using self-adhesive electrodes. The system is intended to be an adjunct to physical therapy interventions where patients play a video game while performing rehabilitation exercises for quadriceps muscle activation and strengthening. In the specific video game used in this protocol, the patient controls birds exploring a virtual/digital environment and completing various tasks, such as collecting food and nesting materials, navigating obstacles, and building a home in the game. Each session begins with calibration of the sensors to establish laterality for the sensors, a resting baseline for the patient by measuring their quadriceps’ EMG when sitting down, and a movement activity measure by measuring quadriceps’ EMG when performing squat. Once calibrated, the patient begins a rehabilitation session. A specific activity in the videogame will be developed for each quadriceps strengthening exercise, and will be assigned to the patient by their PT for each of their exercise sessions during the 8-week rehabilitation program. The birds in the video game would only complete prescribed tasks if target EMG amplitudes were achieved while performing exercises. Sessions end with a workout and progress toward unlocking new features of the game.

The exercises, number of repetitions, sets, and other modifications to each patient rehabilitation session can be made by the physical therapist using the clinician dashboard. Barron Associates game development team created a HIPAA-compliant, cloud-based database for the providers to customize the game, track patient adherence, monitor progress, and transfer data as needed (Figure 1).

Figure 1.

Example screenshots of various aspects of the video game showing activity cues and the bird character interacting within the videogame environment (A-C) and an example of the clinician-facing dashboard (D).

Pre-Clinical Trial Focus Groups

Prior to recruitment for the clinical trial, a series of focus groups were conducted using a semi-structured interview process. Focus group sessions were conducted with small groups of physical therapists to provide feedback on the KneeBRIGHT system including various aspects of the video game and how to best incorporate into clinical practice. Adjustments to the KneeBRIGHT system were made based on feedback received. The subsequent focus groups were mock rehabilitation sessions where a PT and a patient were given the opportunity to navigate a single exercise session using the system. Feedback from both physical therapists and patients were collected regarding usability and acceptability of the KneeBRIGHT system, and changes were implemented to the final version used for this clinical trial. However, patients were not involved in the development of the design, conduct, or reporting of the clinical trial. Questions asked during both the PT focus groups and the PT plus patient focus groups can be found in Supplemental Appendix F.

Adverse Event Reporting and Withdrawal Criteria

Given the parameters and features of the KneeBRIGHT system, this study was evaluated to be minimal risk according to the IRB at UNC. However, in the case of any adverse events or complications relating to use of the investigational device such as abnormally increased knee pain, joint swelling, or muscle fatigue, there is a sport medicine physician assigned to review and provide the standard of care for the adverse event or complication as outlined in the study protocol. Participants will be given the contact information of the study coordinator to reach out in the scenario of any adverse events. Study coordinators will record the adverse event in a secure, password protected, HIPAA-compliant server. Furthermore, potential risks of being in the study and using the KneeBRIGHT system were outlined to patients during the consenting process and they were made aware of a small chance to experience a skin reaction that can manifest as a minor, temporary skin redness and irritation secondary to use of EMG electrodes despite the implementation of an electrode adhesive that has a lower risk of causing the allergic reaction.

Patients who miss 3 or more (out of 8) clinic exercise sessions will be withdrawn from the study. Patients who miss 5 or more (out of 24) exercise sessions total (either home or clinic) will also be withdrawn from the study. Each no-show incidence requires a documented attempt to reschedule by the study coordinator. If patients do not complete 3 home sessions, or if they do not return the surveys sent to them about their home sessions through the REDCap system after 3 documented attempts to contact the patient, they will be withdrawn. To promote retention, patients will receive appointment reminders from an automated patient communication system for their clinic sessions and biweekly or weekly surveys regarding their home sessions.

Data Entry and Management

Study data collected will be entered and managed using REDCap, a secure web-based data collection platform. REDCap is a password protected, HIPAA-compliant platform which is only accessible to authorized personnel. Patient identifier information will be recorded in separate tabs within REDCap, allowing for easy deidentification of the data. Given the study is minimal-risk, to be conducted in a single academic center, have an intended sample size of 60, and the intervention will be used for 8 weeks, a data monitoring committee will not be used. Trial conduct will be monitored by the principal investigator, the study team, and the IRB as is consistent with minimal risk studies. Additionally, An NIH-approved Safety Officer, who is not affiliated with the study, will monitor safety assessments. There are no interim analyses planned or guidelines for stopping the study outside of meeting the target number of patients for recruitment.

Planned Statistical Analysis and Sample Size Considerations

A statistically significant difference in improvements of subjective outcomes after the 10-week trial between the KneeBRIGHT group and the control group will be investigated using the composite KOOS scores. This analysis will not include those patients who were withdrawn from the study. The change in composite KOOS socre will be the primary outcome measured for the study, with all other analyses being secondary. Pre/post intervention KOOS scores will be analyzed via Analysis of Covariance (ANCOVA). The null hypothesis will test if the delta values are equal to zero and another null hypothesis will test if the delta values are the same or less for the KneeBRIGHT group compared to the control group. Both hypotheses will have P ⩽ .05 as the rejection criteria. Covariate analysis of participants sex, age, baseline functional ability, and assigned clinician will evaluate the effects of these characteristics on outcome metrics. Having at least 25 participants per group will achieve a statistical power of 80% to detect a change of 12 points in the KOOS score. This is reasonable given that this value is lower than the minimal detectable change in KOOS scores for knee OA patients which ranges from 13.4 for the pain value and 21.1 for the quality-of-life value.⁵

A statistically significant difference in increased levels of engagement in the KneeBRIGHT group compared to the control will be investigated using the patient activation survey results. The survey scores will be totaled to produce composite scores, and these values will be analyzed using a linear mixed model. A P ⩽ .05 will be the rejection criteria.

A statistically significant difference in increased home exercise adherence in the KneeBRIGHT group compared to the control will be investigated using the timing data for exercises in both groups. Mean usage time in the KneeBRIGHT group will be compared to the mean exercise time in the control group using a student’s paired t-test with a P ⩽ .05 as the rejection criteria.

A statistically significant difference in improvements in objective testing pre and post rehabilitation between the control and KneeBRIGHT groups will be investigated using ANCOVA. ANCOVA will be run for center of pressure distance and area for single leg balance. Center of pressure distance, area, and percent weight bearing per limb will be analyzed for double leg balance and squat. Maximum repetitions of sit-to-stand, 6-minute walk distance, isokinetic and isometric peak torque will be analyzed as well using ANCOVA. All comparisons will have a P ⩽ .05 as the rejection criteria. Covariate analysis of participants sex, age, baseline functional ability, and assigned clinician will evaluate the effects of these characteristics on outcome metrics.

A statistically significant difference in improvements in VAS scores will also be investigated using ANCOVA. The change in VAS in the baseline testing and post rehabilitation testing sessions will be compared to see if any group had a significantly greater decrease in their VAS difference. A P ⩽ .05 will be the rejection criteria and a covariate analysis of participant sex, age, baseline functional ability, and assigned clinician will also be run.

Adverse events between groups will be counted and the difference in the proportion of individuals experiencing an adverse event will be analyzed using a chi-square test for independence to evaluate whether harm is associated with the KneeBRIGHT system. The comparison will again have a P ⩽ .05 as the rejection criteria.

Discussion

Home exercise program adherence is a major obstacle for patients with knee OA looking to optimize the therapeutic value of long-term PT.^19
-23 By providing a more engaging and enjoyable means to complete their home exercise regimens, we aim to provide a novel method to increasing adherence and a means for patients to actualize the benefits of long-term PT for knee OA using the KneeBRIGHT system. We present a clinical trial that builds upon previous research studies by integrating feedback to enhance the gaming experience, address patient concerns, and ensure statistically significant functional efficacy. Through Barron Associates innovative EMG-BF sensor and gameplay software, patients will be able to visualize their performance and have less concern over the initial physical and psychological discomfort of exercise. Through incorporation of a provider dashboard, patients will be tracked and monitored by licensed PTs, increasing their self-confidence in their prescribed exercises.

We anticipate that the strengths of this study will be its demonstration of increased home exercise adherence and patient engagement in patients using the KneeBRIGHT system, along with possible improvements in performance metrics. However, this study is not without its limitations. Firstly, the study only utilizes a single trial for the single leg and double leg balance tasks during baseline testing. This was due to constraints such as session time and fatigue in the older adult population targeted for the study. We aim to minimize this by focusing any analyses on group comparisons and caution future readers of the results to avoid making interpretations based on any individual balance performance outcomes. Secondly, the 6MWT is done around a 12 m loop instead of the 30 m loop recommended by the American Thoracic Society. This may influence test outcomes due to the more frequent turns and limit our comparability of the 6MWT results with other 6MWT done in other studies. This limitation is due to the physical limitations of the laboratory, but given the same instructions and environment conducted for all participants, we believe the internal validity is reliable and some of the concern is mitigated. Thirdly, the maximum effort knee extensions and flexion repetitions will only be done once per leg for participants where a learning effect may be in play and underestimate peak torque. This was again due to feasibility constraints such as time and fatigue in the elderly patient population, but we plan to mitigate this by giving clear instructions to the patients beforehand and providing verbal encouragement during the repetitions. Lastly, since the outcome assessors in this study are aware of the intervention they received in the KOOS survey, the patient reported outcome is not a blinded assessment. As such, the results may be subject to response or expectation bias and interpretation of the results should incorporate this. However, given that participants aren’t provided their KOOS scores and there are months of time between the 2 testing sessions, this bias would be minimal. The results of this study could prove a promising avenue for growth in the field of physical therapy delivery and administration, especially for patients facing obstacles for access to in-person care.

Supplemental Material

sj-docx-1-rpo-10.1177_27536351261435821 – Supplemental material for Knee Biofeedback Rehabilitation Interface for Game-based Home Therapy (KneeBRIGHT) in Patients with Knee Osteoarthritis: A Protocol for Evaluating the KneeBRIGHT System via Randomized, Controlled Clinical Trial

Supplemental material, sj-docx-1-rpo-10.1177_27536351261435821 for Knee Biofeedback Rehabilitation Interface for Game-based Home Therapy (KneeBRIGHT) in Patients with Knee Osteoarthritis: A Protocol for Evaluating the KneeBRIGHT System via Randomized, Controlled Clinical Trial by Aziz Norbekov, Eileen Krepkovich, Carla Hill, David Berkoff, Nailah Adams, Devin K. Kelly, Andrew Jackman, John Kane, Ashley Hanson and Joe M. Hart in Advances in Rehabilitation Science and Practice

Footnotes

ORCID iD

Aziz Norbekov

Ethical Considerations

The study protocol was reviewed and approved by the University of North Carolina Institutional Review Board (IRB #23-2596).

Consent to Participate

All participants provided written informed consent prior to enrollment and data collection.

Consent for Publication

Not applicable. The manuscript contains no identifiable personal data and all images used are of the author and have been anonymized.

Funding

The authors disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This work was supported by the National Institute on Aging (Grant number 5R44AG062069-05). The funding agency has no role in the design, conduct, or reporting of this study.

Declaration of Conflicting Interests

The authors declared the following potential conflicts of interest with respect to the research, authorship, and/or publication of this article: Eileen Krepkovich and Andrew Jackman are salaried employees of Barron Associates, Inc., which is a for-profit company and the grantee of the National Institute of Aging, which sponsored this research. Barron Associates, Inc. is the owner of intellectual property involved in this research. The remaining authors, including the principal investigator Dr. Hart, declare no potential conflicts of interest with respect to research, authorship, and/or publication of this article.

Data Availability Statement

The data to be collected during this study is available for the corresponding author upon reasonable request. Due to the inclusion of identifiable health information, the data is not publicly available.

Supplemental Material

Supplemental material for this article is available online.

References

Yelin

Murphy

Cisternas

Foreman

Pasta

Helmick

CG.

Medical care expenditures and earnings losses among persons with arthritis and other rheumatic conditions in 2003, and comparisons with 1997. Arthritis Rheum. 2007;56(5):1397-1407.

Chan

Flynn

A systematic review of the incidence, prevalence, costs, and activity and work limitations of amputation, osteoarthritis, rheumatoid arthritis, back pain, multiple sclerosis, spinal cord injury, stroke, and traumatic brain injury in the United States: a 2019 update. Arch Phys Med Rehabil. 2021;102(1):115-131.

Orthopaedic Research Society. The Hidden Impact of Musculoskeletal Disorders on Americans. Burden of Musculoskeletal Diseases in the United States (BMUS). 2024. Accessed August 20, 2025. https://www.ors.org/boneandjointburden/

Hootman

Helmick

CG.

Projections of US prevalence of arthritis and associated activity limitations. Arthritis Rheum. 2006;54(1):226-229.

GBD 2015 Disease and Injury Incidence and Prevalence Collaborators. Global, regional, and national incidence, prevalence, and years lived with disability for 310 diseases and injuries, 1990-2015: a systematic analysis for the Global Burden of Disease Study 2015. Lancet. 2016;388(10053):1545-1602.

Long

Liu

Yin

, et al. Prevalence trends of Site-specific osteoarthritis from 1990 to 2019: Findings from the Global Burden of Disease Study 2019. Arthritis Rheumatol. 2022;74(7):1172-1183.

Aboulenain

Saber

AY.

Primary osteoarthritis. In: Statpearls [Internet]. Treasure Island (FL) StatPearls Publishing; 2025. Accessed September 17, 2025. http://www.ncbi.nlm.nih.gov/books/NBK557808/

Kolasinski

Neogi

Hochberg

, et al. 2019 American College of Rheumatology/Arthritis Foundation guideline for the management of osteoarthritis of the hand, hip, and knee. Arthritis Rheumatol. 2020;72(2):220-233.

Rausch Osthoff

Niedermann

Braun

, et al. 2018 EULAR recommendations for physical activity in people with inflammatory arthritis and osteoarthritis. Ann Rheum Dis. 2018;77(9):1251-1260.

10.

Fransen

McConnell

Harmer

Van der Esch

Simic

Bennell

KL.

Exercise for osteoarthritis of the knee: a Cochrane systematic review. Br J Sports Med. 2015;49(24):1554-1557.

11.

Deyle

Henderson

Matekel

Ryder

Garber

Allison

SC.

Effectiveness of manual physical therapy and exercise in osteoarthritis of the knee. A randomized, controlled trial. Ann Intern Med. 2000;132(3):173-181.

12.

Foster

Nicholls

Holden

Healey

Hay

EM.

Improving the effectiveness of exercise therapy for adults with knee osteoarthritis: A Pragmatic Randomized Controlled Trial (BEEP Trial). Arch Rehabil Res Clin Transl. 2023;5(2):100266.

13.

Kovar

Allegrante

MacKenzie

Peterson

Gutin

Charlson

ME.

Supervised fitness walking in patients with osteoarthritis of the knee. A randomized, controlled trial. Ann Intern Med. 1992;116(7):529-534.

14.

de la Barra Ortiz

Matamala

López Inostroza

Lobos Araya

Núñez Mondaca

Efficacy of biofeedback in rehabilitation of musculoskeletal disorders: a systematic review. Adv Rehabil. 2022;36(1):41-69.

15.

Miri

Tahami

Veisi

Assessing the effectiveness of EMG-biofeedback on an isometric strengthening program in individuals with multiple sclerosis. Multiple Scler Relat Disord. 2025;93:106193.

16.

Palazzo

Klinger

Dorner

, et al. Barriers to home-based exercise program adherence with chronic low back pain: patient expectations regarding new technologies. Ann Phys Rehabil Med. 2016;59(2):107-113.

17.

Argent

Daly

Caulfield

Patient involvement with home-based exercise programs: can connected health interventions influence adherence?

JMIR Mhealth Uhealth. 2018;6(3):e47.

18.

Lee

Song

Hootman

, et al. Obesity and other modifiable factors for physical inactivity measured by accelerometer in adults with knee osteoarthritis. Arthritis Care Res. 2013;65(1):53-61.

19.

Bossen

Buskermolen

Veenhof

de Bakker

Dekker

Adherence to a web-based physical activity intervention for patients with knee and/or hip osteoarthritis: a mixed method study. J Med Internet Res. 2013;15(10):e223.

20.

Bossen

Veenhof

Beek

KEV

Spreeuwenberg

Dekker

Bakker

DHD

. Effectiveness of a web-based physical activity intervention in patients with knee and/or hip osteoarthritis: randomized controlled trial. J Med Internet Res. 2013;15(11):e2662.

21.

Campbell

Evans

Tucker

Quilty

Dieppe

Donovan

JL.

Why don’t patients do their exercises? Understanding non-compliance with physiotherapy in patients with osteoarthritis of the knee. J Epidemiol Community Health. 2001;55(2):132-138.

22.

Marks

Knee osteoarthritis and exercise adherence: a review. Curr Aging Sci. 2012;5(1):72-83.

23.

Pisters

Veenhof

Schellevis

Twisk

Dekker

De Bakker

DH.

Exercise adherence improving long-term patient outcome in patients with osteoarthritis of the hip and/or knee. Arthritis Care Res. 2010;62(8):1087-1094.

24.

Alfieri

da Silva Dias

de Oliveira

Battistella

LR.

Gamification in musculoskeletal rehabilitation. Curr Rev Musculoskelet Med. 2022;15(6):629-636.

25.

Stamm

Dahms

Müller-Werdan

Virtual reality in pain therapy: a requirements analysis for older adults with chronic back pain. J Neuroeng Rehabil. 2020;17(1):129.

26.

Then

Shivdas

Tunku Ahmad Yahaya

Ab Razak

Choo

PT.

Gamification in rehabilitation of metacarpal fracture using cost-effective end-user device: a randomized controlled trial. J Hand Ther. 2020;33(2):235-242.

27.

Ambrosino

Iannuzzi

Formisano

, et al. Exergaming as an additional tool in rehabilitation of young patients with rheumatoid arthritis: a pilot randomized controlled trial. Games Health J. 2020;9(5):368-375.

28.

Clausen

Nahen

Horstmann

, et al. Improving maximal strength in the initial postoperative phase after anterior cruciate ligament reconstruction surgery: randomized controlled trial of an app-based serious gaming approach. JMIR Serious Games. 2020;8(1):e14282.

29.

Afzal

Ahmad

Mohseni Bandpei

Gilani

Hanif

Waqas

MS.

Effects of virtual reality exercises and routine physical therapy on pain intensity and functional disability in patients with chronic low back pain. J Pak Med Assoc. 2022;72(3):413-417.

30.

de Carvalho

Carvalho

Alves

RDS

, et al. Analysis of the muscular activity, peak torque in the lower limbs, and static balance after virtual rehabilitation in women with fibromyalgia: a randomized controlled study. Games Health J. 2021;10(3):190-197.

31.

Krepkovich

Kaur

Mangum

, et al. Feasibility of a novel video game-based electromyography biofeedback system in patients with knee osteoarthritis. J Sport Rehabil. 2022;31:937-942. doi:10.1123/jsr.2021-0397

32.

Kaur

Krepkovich

Saliba

Bruce

Thompson

Hart

Video Game-Based EMG-biofeedback interventions in patients with knee osteoarthritis [poster]. Presented at: American Physical Therapy Association; February 2-5, 2022; San Antonio, TX. https://www.researchgate.net/publication/359064790_Video_Game-Based_EMG-biofeedback_interventions_in_patients_with_knee_osteoarthritis

33.

Juhl

Christensen

Roos

Zhang

Lund

Impact of exercise type and dose on pain and disability in knee osteoarthritis: a systematic review and meta-regression analysis of randomized controlled trials. Arthritis Rheumatol. 2014;66(3):622-636.

34.

Petersson

Boegård

Saxne

Silman

Svensson

Radiographic osteoarthritis of the knee classified by the Ahlbäck and Kellgren & Lawrence systems for the tibiofemoral joint in people aged 35-54 years with chronic knee pain. Ann Rheum Dis. 1997;56(8):493-496.

35.

Centers for Disease Control and Prevention, National Center for Injury Prevention and Control. Stopping Elderly Accidents, Deaths & Injuries (STEADI) Initiative. 30-Second Chair Stand Assessment; 2017. Accessed August 27, 2025. https://www.cdc.gov/steadi/media/pdfs/STEADI-Assessment-30Sec-508.pdf

36.

Matos Casano

Ahmed

Anjum

Six-minute walk test. In: Statpearls [Internet]. StatPearls Publishing; 2025. http://www.ncbi.nlm.nih.gov/books/NBK576420/

37.

Collins

Misra

Felson

Crossley

Roos

EM.

Measures of knee function: International Knee Documentation Committee (IKDC) subjective knee evaluation form, knee injury and osteoarthritis outcome score (KOOS), knee injury and osteoarthritis outcome score physical function short form (KOOS-PS), knee outcome survey activities of daily living scale (KOS-ADL), Lysholm Knee scoring scale, Oxford Knee Score (OKS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Activity Rating Scale (ARS), and Tegner Activity Score (TAS). Arthritis Care Res. 2011;63 Suppl 11(0 11):S208-S228.

38.

Harris

Taylor

Thielke

Payne

Gonzalez

Conde

JG.

Research electronic data capture (REDCap)–a metadata-driven methodology and workflow process for providing translational research informatics support. J Biomed Inform. 2009;42(2):377-381.

39.

Hibbard

Stockard

Mahoney

Tusler

Development of the Patient Activation Measure (PAM): conceptualizing and measuring activation in patients and consumers. Health Serv Res. 2004;39(4 Pt 1):1005-1026.

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