IntroductionIntroducciónالمقدمة

Subacromial impingement syndrome (SIS) represents the most common cause of shoulder pain, accounting for approximately 36% of all shoulder pathologies [1,2]. SIS refers to pain and functional limitation associated with structures within the subacromial space [1,2]. Contemporary literature increasingly favours the term “subacromial pain syndrome” (SAPS) to reflect the multifactorial and often non-structural nature of this condition; however, the term SIS is retained in this study for consistency with the diagnostic framework used during participant selection [3].

A primary extrinsic contributor to SIS is altered scapulothoracic rhythm [2]. Scapular upward rotation contributes approximately 30–40% of scapulohumeral rhythm, and reductions in this motion are strongly associated with various shoulder pathologies [4]. Effective treatment strategies should focus on assessing and correcting scapular positioning and restoring optimal scapulohumeral mechanics [2,4].

Mobilization with movement (MWM) differs from traditional passive joint mobilization techniques in that it incorporates active patient movement during the application of the mobilization [10–14]. MWM has demonstrated superior immediate effects on pain reduction and range of motion compared to passive and sham techniques in peripheral joint conditions [10–14]. However, limited evidence exists evaluating the duration of these effects and the potential additive benefits when combined with neuromuscular reeducation strategies [11,13].

Purpose: To evaluate the effects of a single session of MWM alone compared with MWM combined with neuromuscular reeducation exercise on pain, active shoulder flexion range of motion (AROM), and the duration of these outcomes in recreational athletes with subacromial impingement syndrome.

MethodsMétodosالمنهجية

2.1Study Design

This quasi-experimental intervention utilised an ABAC single-subject withdrawal design across four participants, with each participant serving as their own control. Ethical approval was obtained from the Concordia University Wisconsin Institutional Review Board (IRB #1602982-1). All participants provided written informed consent prior to participation.

2.2Participants

Four recreational athletes (2 males, 2 females; ages 19–21) diagnosed with SIS were recruited from Concordia University Wisconsin. A recreational athlete was defined as an individual who participates in athletics at a recreational level, trains 1–4 times per week, and does not exceed eight hours per week in a single activity [16].

2.3Selection Criteria

Participants were included if they were cleared for physical activity and scored between 5 and 10 on the Tegner Activity Level Scale. Exclusion criteria included: upper extremity or cervical spine surgery within the past year; prior diagnosis of adhesive capsulitis, grade III rotator cuff tear, biceps tendon tear, labral tear, or hooked acromion; upper extremity fracture within the past year; history of systemic or neurological disorders, cervical radiculopathy, cancer, active inflammatory disease, or neuromuscular disorders; and presence of numbness or tingling in the upper extremity.

Eligible participants underwent clinical screening using an orthopedic test cluster for SIS: Hawkins-Kennedy Test, Neer’s Sign, Empty Can Test, Painful Arc Sign, and External Rotation Resistance test (sensitivity 0.75; specificity 0.74; ≥3 positive tests required) [17].

2.4Outcome Measures

Active Shoulder Flexion AROM: Measured using an Acumar digital inclinometer (ICC = 0.90–0.98) [19,20]. Participants positioned standing; inclinometer at midpoint of humeral shaft. Instruction: “Stand upright, position your thumb toward the ceiling, and raise your arm forward as far as possible without reaching pain.”

Global Rating of Change Scale (GROC): 15-point self-reported pain scale; MCID ≥5 points [21]. Administered immediately post-intervention and at 24-hour follow-up.

2.5Study Timeline

2.6Interventions

Intervention B — MWM Alone (45 min): MWM performed using clinician-applied posterior-to-anterior scapular fixation (Figure 1). Active glenohumeral flexion; 4/2/2 tempo at 60 BPM; 3 sets × 20 repetitions; 30 s rest between sets. Post-intervention: GROC reassessed; AROM recorded every minute for 30 minutes.

Figure 1.

Clinician-applied scapular anterior-to-posterior fixation during mobilization with movement (MWM), demonstrating progressive mechanical positioning.

Intervention C — MWM + Neuromuscular Reeducation (75 min): Identical MWM protocol as Phase B, followed immediately by neuromuscular reeducation exercises targeting the serratus anterior, pectoralis major/minor, and upper/lower trapezius (Figure 2) [25–27]:

• Forward flexion with horizontal abduction (130°)
• Scaption with horizontal abduction (130°)
• Elevation with external rotation (90°)
• Serratus punch (shoulder protraction)

Protocol: 3 sets × 10 repetitions per exercise; 60 s rest between sets; 4/2/2 tempo at 60 BPM; red resistance band [28].

Figure 2.

Neuromuscular Reeducation Exercises: (A) Forward flexion with horizontal abduction. (B) Scaption with horizontal abduction. (C) Elevation plus external rotation. (D) Serratus punch.

2.7Statistical Analysis

Two-band standard deviation method [30]. Significance: two consecutive data points outside upper/lower two-SD bands. “Return to baseline”: two consecutive AROM measurements within baseline SD range. SD values: Participant 1: ±12.15°; Participant 2: ±3.15°; Participant 3: ±7.05°; Participant 4: ±5.95°.

ResultsResultadosالنتائج

Nine participants were initially recruited; three did not meet inclusion criteria; two withdrew due to external conflicts. Four participants completed the study and were included in the final analysis.

3.1GROC Results

Clinically meaningful improvements in pain (MCID ≥5 points) were observed in Participant 1 following MWM alone, and in Participants 1 and 4 following the combined intervention. At 24-hour follow-up, sustained improvement was observed only in Participant 4 following the combined intervention.

3.2AROM Results

Statistically significant increases in AROM were observed in Participants 1, 2, and 4 following both intervention conditions. The MWM-plus-exercise condition produced greater average increases in AROM (23.2°) compared to MWM alone (8.4°), along with longer-lasting effects (mean duration: 25.5 minutes vs. 15 minutes). Participant 3 demonstrated no measurable duration of improvement for either intervention. Participants 2 and 4 maintained improvements beyond 30 minutes, with extended effects observed at the 24-hour follow-up following the combined intervention.

Figure 3.

Minute-by-minute shoulder flexion AROM values across baseline (A1, A2) and intervention (B, C) phases for all four participants, with upper and lower two-band standard deviation limits. (Note: Figure recreated by JMMBS for enhanced visual clarity.)

DiscussionDiscusiónالمناقشة

This study provides novel insight into the standalone and combined effects of MWM and neuromuscular reeducation in recreational athletes with SIS. Both intervention strategies resulted in improvements in pain and range of motion; however, the combined MWM-plus-exercise condition produced superior outcomes in both magnitude and duration. Substantial inter-participant variability was observed, emphasising the importance of individualised treatment strategies.

4.1Patient-Reported Pain

This study represents the first investigation utilising the GROC scale to evaluate the effectiveness of MWM in individuals with SIS. From a mechanistic perspective, MWM may induce hypoalgesic effects through peripheral mechanoreceptor stimulation and modulation of nociceptive input via gate control mechanisms [35]. The incorporation of active movement may facilitate neuromuscular reorganisation and improved proprioceptive mapping, while scapular repositioning may optimise force-couple relationships and reduce subacromial compression [36].

4.2Inter-Participant Variability

Participant 3, who demonstrated minimal response, may have exhibited greater structural contributions to impingement that are less responsive to scapular repositioning strategies. Contributing factors may include baseline differences in scapular mechanics, rotator cuff strength, joint mobility, and psychological variables such as fear-avoidance or pain perception.

4.3Glenohumeral Range of Motion

This study is the first to evaluate the short-term duration of MWM effects on pain-free glenohumeral flexion AROM, and the first to apply a single-subject design to investigate MWM effects in the shoulder. The observed immediate improvements are consistent with previous literature [11,13,37,38].

4.4Comparison of Treatment Strategies

The combined MWM-plus-exercise condition demonstrated superior AROM improvement and duration of effect. With the exception of Participant 2, all participants demonstrated greater improvements following the combined intervention. The observed superiority may be attributed to enhanced neuromuscular activation and improved mechanical alignment. From a mechanical perspective, improved coordination between the rotator cuff and scapular stabilisers may enhance moment arm efficiency (τ = r × F), facilitating more controlled and efficient force transfer throughout the kinetic chain.

4.5Clinical Implications

MWM alone: mean 8.4° AROM increase; approximately 15 minutes duration. MWM + exercise: mean 23.2° increase; approximately 25.5 minutes duration. These findings suggest that the addition of neuromuscular reeducation enhances both the magnitude and persistence of treatment effects. The application of MWM, particularly when combined with neuromuscular reeducation, may contribute to improved force-vector alignment and reduction in aberrant joint loading patterns, thereby decreasing subacromial compressive stress.

4.6Limitations

Limitations include: lack of prior literature on duration of MWM effects in SIS; inability to definitively differentiate primary from secondary impingement without imaging; inability to fully control participant adherence outside the study; and individual variability in physiological and psychological responses.

ConclusionConclusiónالخلاصة

This single-subject ABAC withdrawal study provides scientific support for the use of mobilization with movement (MWM), both as a standalone intervention and in combination with neuromuscular reeducation exercise, in the management of recreational athletes presenting with secondary subacromial impingement syndrome (SIS). The addition of neuromuscular reeducation exercise was associated with greater improvements in both the magnitude and duration of pain reduction and AROM gains. Notable inter-individual variability reinforces the importance of individualised clinical decision-making. Further research with larger sample sizes and controlled study designs is warranted.

Author Biographical Notes

Declarations

References

All references formatted in accordance with APA 7th Edition.

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