Effects of Knowledge of Results Intervention in Rotator Cuff-Related Shoulder Pain

Effects of Knowledge of Results as an Augmented Feedback Intervention on Clinical Outcomes, Physical Performance and Psychosocial Parameters in Rotator Cuff-Related Shoulder Pain: A Randomized Controlled Trial

Previous research demonstrates that augmented feedback effectively enhances motor skills and performance in both healthy individuals and those with neurological conditions. However, while the role of Knowledge of Results (KR)-a specific augmented feedback strategy-in supporting motor learning is well-established, its efficacy in improving rehabilitation outcomes remains unclear. Notably, there is a lack of studies in the current literature investigating the effects of augmented feedback strategies in individuals with rotator cuff-related shoulder pain (RCRSP). Given the complex and multidimensional pain neurophysiology associated with RCRSP, a KR intervention is hypothesized to hold significant potential for restoring motor control, correcting pain-driven maladaptive movement patterns, alleviating pain, and recovering function in this population. Therefore, the primary objective of this study is to investigate the effects of a KR intervention on clinical outcomes, physical performance, and psychosocial parameters in individuals with RCRSP. The study is designed as a two-arm, prospective, parallel-group, randomized controlled trial. Eligible participants meeting the inclusion criteria will be randomly allocated to either the intervention (n = 28; standard rehabilitation program+ KR intervention)or control group (n = 28; standard rehabilitation program) using computer-based randomization software (www.sealedenvelope.com). Both groups will undergo the same routine exercise-based treatment protocol over an 8-week period, consisting of one physiotherapist-supervised session per week and a home exercise program on the remaining days. While the control group will solely receive the standard rehabilitation program, the intervention group will additionally receive the KR intervention, wherein their assessment results will be regularly shared throughout the treatment process. Conversely, these data will only be disclosed to the control group participants at the conclusion of the 8-week intervention.

Study Overview

• Status: Enrolling by invitation
• Conditions: Rehabilitation; Rotator Cuff-related Shoulder Pain; Augmented Feedback
• Intervention / Treatment: Behavioral: Knowledge of Results; Other: Standart Rehabilitation

Detailed Description

A comprehensive, multidimensional assessment protocol will be conducted to evaluate the clinical, neuromuscular, sensorimotor, and psychosocial effects of the intervention. To ensure consistency, all measurements will be performed by the same physiotherapist. Pain intensity (VAS), disability (SPADI), active and pain-free range of motion (using a smartphone inclinometer for flexion, abduction, and internal/external rotation), isometric external rotation strength (via a handheld dynamometer), and the Global Rating of Change (GROC) will be recorded at baseline and continuously monitored prior to each supervised session. Additionally, at baseline and after the 8-week intervention, further pre- and post-intervention assessments will be conducted. These include isometric external rotation, internal rotation, and scaption strength using a strap-fixated handheld dynamometer (EasyForce), with strength tests being terminated if pain exceeds 5/10 on the VAS. Sensorimotor function will be evaluated by measuring shoulder proprioception via Active Joint Position Sense (AJPS) at a 45° target angle in a 90°/90° position, alongside posterior shoulder endurance tested in a prone position holding 2% of body weight. Psychosocial and behavioral parameters will also be assessed, including kinesiophobia (Tampa Scale of Kinesiophobia), pain catastrophizing (Pain Catastrophizing Scale), avoidance behaviors (ADAP-TR and ASAP-Shoulder scales), patient satisfaction (Single Assessment Numeric Evaluation - SANE), and self-efficacy (Pain Self-Efficacy Questionnaire - PSEQ).

Both groups will undergo an 8-week multimodal, evidence-based shoulder rehabilitation program consisting of one supervised clinical session per week and a home exercise program performed three times daily. The protocol includes patient education focusing on pathophysiology, pain management, and activity modification to improve posture and restrict heavy overhead activities. It also incorporates cryotherapy as needed, and targeted manual therapy involving soft tissue release for the long head of the biceps, pectoralis minor, posterior capsule, and supraspinatus. Furthermore, a structured, pain-guided (VAS < 4/10) bilateral progressive exercise therapy program will be implemented. This comprises stretching of the upper trapezius, pectoralis minor, and posterior capsule for 3 sets of 30 seconds, alongside a specific regimen of progressive strengthening and neuromuscular control exercises. The exercise protocol specifically includes bilateral scapular retraction, internal and external rotation, the push-up plus, the full can exercise, bilateral external rotation with elevation using a resistance band, the lawnmower with diagonal squat, the robbery with squat, and proprioceptive exercises utilizing a laser pointer (Motion Guidance). Exercises will be performed for 3 sets of 10 repetitions during weeks 1 to 4, and progressed to 3 sets of 12 repetitions during weeks 5 to 8. Resistance is established using 30% of 1-Repetition Maximum (1-RM) for free weights or an OMNI-RES EB score of 3-5 for elastic bands. To optimize muscle activation and minimize compensation, movements will initially be restricted to under 90° of elevation, with the full range of motion restored before any increase in external load.

The Knowledge of Results intervention will be administered exclusively to the intervention group once a week for 8 weeks, immediately prior to each supervised treatment session, whereas the control group will receive no such augmented feedback. The objective of this intervention is to systematically provide participants with objective, quantifiable data regarding their task results, enabling them to recognize their performance and cumulative progress through concrete metrics. Upon the completion of the routine assessments the physiotherapist will verbally and numerically report the patient's results for pain intensity (VAS), disability (SPADI), pain-free range of motion, isometric external rotation strength, and perceived recovery (GROC). To maximize patient focus and emphasize the importance of the information, this feedback will be delivered immediately after each assessment set using a clear, emphasized, and slightly elevated tone of voice to distinguish it from ambient noise. For physical performance metrics (range of motion and strength), participants will perform three repetitions; once the joint is returned to the starting position, the physiotherapist will calculate and disclose the arithmetic mean of the three trials, alongside the absolute change compared to the previous week's measurement. Similarly, for clinical parameters (pain, disability, and GROC), both the current scores and the calculated weekly differences will be explicitly communicated. This standardized approach ensures that participants receive immediate, explicit insight into both their current session performance and their longitudinal weekly improvements. For example, "your pain level this week is 4 out of 10, which is a 10% decrease compared to last week."

• Study Type: Interventional
• Enrollment (Estimated): 56
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Turkey (Türkiye)
  • Sıhhıye
    • Ankara, Sıhhıye, Turkey (Türkiye), 06100
      • Hacettepe University, Faculty of Physical Therapy and Rehabilitation,, Ankara, Sıhhıye 06100

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Aged between 18 and 35 years;
• Presence of unilateral shoulder pain lasting for at least 3 months;
• Confirmed diagnosis of at least one of the following conditions by a physician, based on clinical evaluation and magnetic resonance imaging (MRI) or ultrasonography (USG) findings: subacromial impingement syndrome, subacromial bursitis, rotator cuff tendinopathy, or partial rotator cuff tear (< 1 cm);
• Presence of a positive painful arc during flexion or abduction, at least one positive impingement test (Neer or Hawkins-Kennedy), and provocation of symptoms during resisted humeral external rotation, abduction, or scapular plane elevation at 90° of elevation;
• A physical activity score of 5 or higher according to the Tegner Activity Level Scale.

Exclusion Criteria:

• Presence of bilateral shoulder pain;
• Presence of a full-thickness or massive rotator cuff tear;
• History of shoulder trauma, fracture, or instability;
• Restriction in passive range of motion;
• Receipt of any injection to the shoulder joint within the previous 6 weeks;
• History of previous shoulder surgery or dislocation;
• Pregnancy;
• Presence of cervical radiculopathy symptoms or peripheral nerve entrapment syndromes;
• A score of 14 or higher on the Beck Depression Inventory-II;
• Diagnosis of hypertension, cardiovascular disease, peripheral vascular disease, history of deep vein thrombosis, neurological disorders, systemic inflammation, diabetes, cancer, or rheumatological diseases;
• Presence of obesity or metabolic syndrome;
• Participation in any rehabilitation program for a shoulder problem within the past year;
• Unwillingness to participate in the study (or failure to provide informed consent).

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Standart rehabilitation + Knowledge of Results; All participants will undergo an 8-week standard shoulder rehabilitation program comprising patient education, manual therapy, and structured progressive exercise. In addition to this standard protocol, the intervention group will receive a KR intervention, administered immediately prior to each weekly supervised session. Accordingly, parameters routinely assessed before each session-namely, pain intensity (VAS), disability level (SPADI), active and pain-free range of motion, isometric external rotation strength, and the Global Rating of Change (GROC)-will be analyzed in real-time. Immediately following the completion of these assessments, the physiotherapist will verbally and numerically communicate the current measurement results to the patient, alongside the absolute change recorded compared to the previous week. To ensure the patient's full attention is directed toward the data, this feedback will be delivered using a clear and emphasized tone of voice.	Behavioral: Knowledge of Results; Knowledge of Results (KR) is an augmented feedback strategy designed to provide patients with objective, quantifiable data regarding their clinical and physical progress. In this study, the KR intervention will be administered weekly, immediately prior to each supervised treatment session. After the completion of routine pre-session assessments (including pain intensity, disability level, range of motion, isometric strength, and GROC), the physiotherapist will verbally and numerically communicate the patient's current scores, alongside the absolute change recorded compared to the previous week. To maximize the patient's focus on their cumulative recovery, this feedback will be delivered directly and explicitly using a clear, emphasized tone of voice. For example, "your pain level this week is 4 out of 10, which is a 10% decrease compared to last week".; Other: Standart Rehabilitation; Participants allocated to the control group will solely undergo the standard 8-week shoulder rehabilitation program, which comprises patient education, targeted manual therapy, and the structured progressive exercise regimen, identical to the intervention group. To isolate the effects of the augmented feedback, the physiotherapist will strictly withhold the current measurement results and any information regarding their weekly progress.
Active Comparator: Standart rehabilitation; Participants allocated to the control group will solely undergo the standard 8-week shoulder rehabilitation program, which comprises patient education, targeted manual therapy, and the structured progressive exercise regimen, identical to the intervention group. Although these participants will attend the same weekly supervised sessions and undergo the exact same routine pre-session assessments-including pain intensity (VAS), disability level (SPADI), active and pain-free range of motion, isometric external rotation strength, and the Global Rating of Change (GROC)-they will not receive the Knowledge of Results (KR) intervention. All clinical and physical performance data will only be disclosed to the control group participants upon the full completion of the 8-week intervention period.	Other: Standart Rehabilitation; Participants allocated to the control group will solely undergo the standard 8-week shoulder rehabilitation program, which comprises patient education, targeted manual therapy, and the structured progressive exercise regimen, identical to the intervention group. To isolate the effects of the augmented feedback, the physiotherapist will strictly withhold the current measurement results and any information regarding their weekly progress.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Pain Intensity	Participants' pain intensity at rest, at night, and during activity will be evaluated using the Visual Analog Scale (VAS). The VAS consists of a 10-cm continuous horizontal line, anchored by "0 = no pain" at the left extremity and "10 = worst imaginable pain" at the right extremity. Participants will be instructed to place a mark on the line that corresponds to their perceived level of pain.	Baseline, up to 8 weeks, at 8 weeks
Disability	Participants' disability levels will be evaluated using The Shoulder Pain and Disability Index (SPADI). SPADI is a self-reported questionnaire designed to assess pain severity and the level of functional limitation in activities of daily living among individuals experiencing shoulder pain. The instrument consists of a total of 13 items divided into two subscales: pain (5 items) and disability (8 items). Each item is evaluated using a visual analog scale ranging from 0 (no pain or no difficulty) to 10 (worst imaginable pain or extreme difficulty).	Baseline, up to 8 weeks, at 8 weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Perceived Recovery	The perceived rate of recovery will be evaluated using the Global Rating of Change (GROC) scale. The GROC is an instrument designed to assess the change in a patient's clinical condition over time-indicating deterioration, no change, or improvement-and quantitatively expresses the magnitude of perceived change following treatment. The scale consists of a 15-point Likert-type structure ranging from -7 ("much worse") to +7 ("much better"), with a score of 0 representing "no change."	Baseline, up to 8 weeks, at 8 weeks
Range of Motion	Participants' active and pain-free active shoulder range of motion will be evaluated using a smartphone inclinometer.	Baseline, up to 8 weeks, at 8 weeks
Shoulder Muscle Strength	Isometric strength of the participants' shoulder internal and external rotators, as well as scapular plane elevation (scaption), will be measured using the EasyForce handheld dynamometer (Meloq Devices, Stockholm, Sweden). The EasyForce is a strap-fixated handheld dynamometer that continuously records tension force. Each test will be performed for 3 repetitions lasting 5 seconds each, and the mean peak force will be recorded in Newtons (N). Additionally, the internal-to-external rotation strength ratio (IR/ER) will be calculated.	Baseline and at 8 weeks
Proprioception	Shoulder proprioception will be evaluated bilaterally via the Active Joint Position Sense (AJPS) method using a smartphone inclinometer. Measurements for internal and external rotation will be conducted in a supine position with the shoulder at 90° of abduction and the elbow at 90° of flexion (the 90°/90° position), utilizing a 45° target angle.	Baseline and at 8 weeks
Posterior Shoulder Endurance	To evaluate participants' shoulder muscle endurance, the Posterior Shoulder Endurance Test will be administered. The test will be performed with the participant in a prone position, with the shoulder in 90° of abduction and external rotation. Participants will be instructed to lift a dumbbell corresponding to 2% of their body weight with their thumb pointing upward, and to maintain this position for as long as possible. The time elapsed from the initial contact with the target until the moment the participant can no longer maintain that contact will be recorded in seconds.	Baseline and at 8 weeks
Kinesiophobia	Kinesiophobia is defined as the fear of movement or re-injury. To evaluate the kinesiophobia levels of the participants, the Tampa Scale of Kinesiophobia (TSK) will be utilized. The scale consists of 17 items that assess parameters including fear, avoidance, and the perceived risk of injury or re-injury during physical and work-related activities. Each item is scored on a 4-point Likert scale ranging from 1 ("strongly disagree") to 4 ("strongly agree").	Baseline and at 8 weeks
Pain Catastrophizing	The Pain Catastrophizing Scale (PCS) will be used to evaluate participants' negative thoughts and emotions regarding pain. The PCS is a 13-item self-report questionnaire comprising three subscales: helplessness, magnification, and rumination. Each item is scored on a 5-point Likert scale ranging from 0 ("not at all") to 4 ("all the time"). The total score is calculated by summing the responses of all items, yielding a possible score range of 0 to 52.	Baseline and at 8 weeks
Avoidance Behavior	o evaluate participants' avoidance behaviors in daily and sports activities due to shoulder pain, the "Avoidance of Daily Activities Photo Scale for Patients with Shoulder Pain (ADAP-TR Scale)" and the "Avoidance of Sports Activities Photo Scale (ASAP Shoulder Scale)" will be utilized.	Baseline and at 8 weeks
Patient Satisfaction	Patient satisfaction will be evaluated using the Single Assessment Numeric Evaluation (SANE). This metric is determined by the patient's response to the following question: "How would you rate your shoulder today as a percentage of normal? (0% = completely abnormal, 100% = completely normal)." Patients will be instructed to provide their response by reflecting on the condition of their shoulder throughout the rehabilitation program.	Baseline and at 8 weeks
Self-Efficacy	Participants' confidence levels in performing specific activities despite experiencing pain will be evaluated using the Pain Self-Efficacy Questionnaire (PSEQ). The PSEQ is an instrument designed to measure individuals' self-confidence in maintaining various activities despite pain. This questionnaire consists of 10 items and assesses multiple dimensions of self-efficacy related to both social and physical functioning. Each item is scored on a 7-point Likert scale ranging from 0 ("not at all confident") to 6 ("completely confident").	Baseline and at 8 weeks

Collaborators and Investigators

• Sponsor: Elif Turgut

Publications and helpful links

General Publications

• Moinuddin A, Goel A, Sethi Y. The Role of Augmented Feedback on Motor Learning: A Systematic Review. Cureus. 2021 Nov 18;13(11):e19695. doi: 10.7759/cureus.19695. eCollection 2021 Nov.

Study record dates

Study Major Dates

• Study Start (Actual): May 5, 2026
• Primary Completion (Estimated): January 1, 2028
• Study Completion (Estimated): January 1, 2028

Study Registration Dates

• First Submitted: May 16, 2026
• First Submitted That Met QC Criteria: June 2, 2026
• First Posted (Actual): June 8, 2026

Study Record Updates

• Last Update Posted (Actual): June 8, 2026
• Last Update Submitted That Met QC Criteria: June 2, 2026
• Last Verified: June 1, 2026

More Information

Terms related to this study

• Keywords: rehabilitation; shoulder pain; rotator cuff; augmented feedback; knowledge of results
• Additional Relevant MeSH Terms: Pain; Neurologic Manifestations; Musculoskeletal Diseases; Joint Diseases; Arthralgia; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Shoulder Pain
• Other Study ID Numbers: FTREK26/28

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: Individual participant data will not be shared because the informed consent obtained from the participants and the ethics committee approval do not cover the public sharing of raw data.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No