The Efficacy of Partial Squats on Measures of Strength and Explosiveness: An Exploratory Study

Abstract available in the 8th Annual Coaches and Sport Science College

The Impact of Experimental Pain on Shoulder Movement During an Arm Elevated Reaching Task in a Virtual Reality Environment

Background: People with chronic shoulder pain have been shown to present with motor adaptations during arm movements. These adaptations may create abnormal physical stress on shoulder tendons and muscles. However, how and why these adaptations develop from the acute stage of pain is still not well-understood. Objective: To investigate motor adaptations following acute experimental shoulder pain during upper limb reaching. Methods: Forty participants were assigned to the Control or Pain group. They completed a task consisting of reaching targets in a virtual reality environment at three time points: (1) baseline (both groups pain-free), (2) experimental phase (Pain group experiencing acute shoulder pain induced by injecting hypertonic saline into subacromial space), and (3) Post experimental phase (both groups pain-free). Electromyographic (EMG) activity, kinematics, and performance data were collected. Results: The Pain group showed altered movement planning and execution as shown by a significant increased delay to reach muscles EMG peak and a loss of accuracy, compared to controls that have decreased their mean delay to reach muscles peak and improved their movement speed through the phases. The Pain group also showed protective kinematic adaptations using less shoulder elevation and elbow flexion, which persisted when they no longer felt the experimental pain. Conclusion: Acute experimental pain altered movement planning and execution, which affected task performance. Kinematic data also suggest that such adaptations may persist over time, which could explain those observed in chronic pain populations

Asymmetric resting scapular posture in healthy overhead athletes

Context: Observation of the scapular posture is one of the most important components of the physical examination in overhead athletes. Postural asymmetry is typically considered to be associated with injuries. However, asymmetry in the overhead athlete's scapula may be normal due to the dominant use of the limb. Objective: To quantify the differences in resting scapular posture between the dominant and nondominant sides in 3 groups of healthy overhead athletes (baseball pitchers, volleyball players, and tennis players) using an electromagnetic tracking device. Design: Cross-sectional design. Setting: University-based biomechanics laboratory. Patients or Other Participants: A total of 43 players participated, including 15 baseball pitchers, 15 volleyball players, and 13 tennis players. All participants were healthy college-aged men. Intervention(s): Bilateral 3-dimensional scapular kinematics with the arm at rest were measured using an electromagnetic tracking device. Main Outcome Measure(s): Bilateral scapular position and orientation were measured. Between-groups and between-sides differences in each variable were analyzed using separate analyses of variance. Results: In tennis players, the scapula was more protracted on the dominant side than on the nondominant side (P , .05). In all overhead athletes, the dominant-side scapula was more internally rotated (P 5 .001) and anteriorly tilted (P 5 .001) than the nondominant-side scapula was. Conclusions: The dominant-side scapula of the overhead athletes was more internally rotated and anteriorly tilted than the nondominant-side scapula. The dominant-side scapula of the tennis players was more protracted than that on the nondominant side. Clinicians evaluating overhead athletes need to recognize that scapular posture asymmetry in unilateral overhead athletes may be normal. Our results emphasize the importance of the baseline evaluation in this population in order to accurately assess pathologic change in bilateral scapular positions and orientations after injury

Pain Knowledge, Attitudes and Beliefs of Doctor of Physical Therapy Students: Changes Across the Curriculum and the Role of an Elective Pain Science Course

Introduction: Entry-level physical therapist education on pain has been described as lacking. Calls have been made to include pain science courses to address this knowledge gap. Methods: Physical therapist students’ pain knowledge and attitudes were measured using the revised Neurophysiology of Pain Questionnaire (rNPQ) and Pain Attitudes and Beliefs Scale for Physical Therapists (PABS-PT), respectively. Univariate ANOVAs, with post hoc pairwise comparison and effect sizes, were used to measure these aspects over time. Results: Pain knowledge and clinician beliefs were significantly different (p \u3c 0.001) at various curricular timepoints. rNPQ scores increased from 1st to 2nd year (effect size: 1.10), remained similar between years 2 and 3, and improved following the pain course (effect size: 1.25). Biomedical beliefs were similar during years 1, 2 and 3, and declined following the pain course (effect size: 1.56). Conversely, psychosocial belief scores increased from 1st to 2nd year (effect size: 0.82), remained similar between years 2 and 3, and increased following the pain course (effect size: 1.08). Discussion/Conclusions: Physical therapist education, without a dedicated pain science course, may be insufficiently preparing students to treat patients in pain. Educators should consider adopting a dedicated pain science course or substantially bolstering embedded curricular pain content to promote best practice in pain treatment

Agreement and Screening Accuracy Between Physical Therapists Ratings and the Ӧrebro Musculoskeletal Pain Questionnaire in Screening for Risk of Chronic Pain During Musculoskeletal Evaluation

Introduction: Identifying patients at risk for chronic musculoskeletal pain can inform evaluation and treatment decisions. The ability of physical therapists to assess patients’ risk for chronic pain without use of validated tools has been questioned. The Ӧrebro Musculoskeletal Pain Questionnaire (OMPQ) is used to determine risk for chronic pain. Methods: The aim of this pragmatic study was to prospectively quantify the agreement between physical therapists’ assessment of patients’ risk for chronic symptoms compared to the OMPQ. Patients were asked to complete the OMPQ during the initial visit. Physical therapists, blinded to OMPQ risk classification, carried out their usual patient assessment procedures. The physical therapists rated patients as either high or low risk for chronic pain based on their clinical assessment. Agreement between therapist and OMPQ was determined using Cohen’s Kappa (κ) and screening accuracy compared clinician risk to the OMPQ risk classification (reference standard) by way of contingency table analysis. Results: Ninety-six (96) patients’ risk classifications and 15 corresponding physical therapists’ risk estimates were available for analysis. The OMPQ identified a 47% prevalence for high risk of chronic pain. Agreement (κ and 95% confidence interval) between physical therapist rating and OMPQ was slight, κ = 0.272 (0.033–0.421), p = .026. Therapists’ sensitivity and specificity (95% CI) for determining risk classifications were 60.0% (44.3–74.3) and 62.8% (48.1–75.6), respectively. The positive and negative likelihood ratios (95% CI) were 1.61 (1.05–2.47) and 0.64 (0.42–0.97). Discussion: The use of validated self-report questionnaires are recommended to supplement clinician prognosis for patients at risk of chronic musculoskeletal pain

Reported Mechanisms of Shoulder Injury During the Baseball Throw

Background: Shoulder complex injuries are common among overhand throwing athletes. These injuries often manifest as a result of habitual sport performance and often lead to time loss injuries. The mechanisms of these injuries are often non-traumatic and theories on how shoulder injuries manifest differ. Objectives: To describe the proposed mechanisms of commonly reported shoulder injuries as they relate to the phases of the throwing motion. Major findings: Shoulder injuries commonly involve rotator cuff muscles and tendons, scapulothoracic muscles, glenohumeral joint labrum, proximal humeral epiphysis, glenohumeral joint capsule, biceps muscle and tendon, and subacromial bursa. The injuries found in these tissues and their purported mechanisms of injury during the throw vary. Conclusions: The late cocking and deceleration phases have been implicated with the largest number of associated pathologies. Multiple injuries were theorized to occur at more than one phase of the throwing motion. Consensus has not been achieved on the provocative events leading to shoulder injury during the throwing motion

Clinical Measurement of Scapular Upward Rotation in Response to Acute Subacromial Pain

STUDY DESIGN: Block-counterbalanced, repeated-measures crossover study. OBJECTIVES: To assess scapular upward rotation positional adaptations to experimentally induced subacromial pain. BACKGROUND: Existing subacromial pathology is often related to altered scapular kinematics during humeral elevation, such as decreased upward rotation and posterior tilting. These changes have the potential to limit subacromial space and mechanically impinge subacromial structures. Yet, it is unknown whether these changes are the cause or result of injury and what the acute effects of subacromial pain on scapular upward rotation may be. METHODS: Subacromial pain was induced via hypertonic saline injection in 20 participants, aged 18 to 31 years. Scapular upward rotation was measured with a digital inclinometer at rest and at 30°, 60°, 90°, and 120° of humeral elevation during a painful condition and a pain-free condition. Repeated-measures analyses of variance were conducted for scapular upward rotation position, based on condition (pain or control) and humeral position. Post hoc testing was conducted with paired t tests as appropriate. RESULTS: Scapular upward rotation during the pain condition was significantly increased (range of average increase, 3.5°-7.7°) compared to the control condition at all angles of humeral elevation tested. CONCLUSION: Acute subacromial pain elicited an increase in scapular upward rotation at all angles of humeral elevation tested. This adaptation to acute experimental pain may provide protective compensation to subacromial structures during humeral elevation

Extremity Aerobic Exercise as a Treatment for Shoulder Pain

BACKGROUND: Shoulder girdle pain is a common disabling complaint with a high lifetime prevalence. Interventions aimed at decreasing shoulder pain without stressing shoulder girdle structures have the potential to improve participation in multimodal shoulder rehabilitation programs. HYPOTHESIS/PURPOSE: The aim of this study was to determine the acute effects of moderate intensity lower extremity exercise on mechanically induced shoulder pain in individuals without shoulder injury. It was hypothesized that participants would exhibit less shoulder pain, as indicated by increased pain thresholds, following lower extremity exercise. STUDY DESIGN: Repeated measures study. METHODS: Thirty (30) healthy participants were recruited to participate in this study. Pain pressure algometry was used to mechanically induce shoulder pain over the infraspinatus muscle belly. This was performed on the dominant shoulder before and immediately after performing 10 minutes of moderate intensity lower extremity exercise using a recumbent exercise machine. Heart rate and rate of perceived exertion were measured following exercise. Repeated measures ANOVA was used to compare pain pressure threshold scores between the baseline and post-exercise time points. Significance was set at p ≤ 0.05 . Effect size (ES) was calculated using Glass\u27s Δ. RESULTS: Moderate intensity lower extremity aerobic exercise led to significantly (F = 8.471, p = 0.003) decreased evoked shoulder pain in healthy adults with moderate effect sizes (0.30-0.43). CONCLUSIONS: Lower extremity aerobic exercise significantly decreased pain of the infraspinatus in this sample of young healthy participants. Utilization of lower extremity exercise may be of benefit for younger patients to decreased acute shoulder pain. LEVEL OF EVIDENCE: 2b: individual cohort study

The Role of Experimentally-Induced Subacromial Pain on Shoulder Strength and Throwing Accuracy

Shoulder injuries often comprise two separate yet related components, structural tissue damage and pain. The role of each of these components on shoulder function is difficult to ascertain. Experimental pain models allow the assessment of consequences of localized pain when applied to healthy individuals. By understanding the role of pain on shoulder function, clinicians will be able to more efficiently assess and treat shoulder injuries. The objective of the study was to evaluate the role of experimentally-induced sub-acromial pain on shoulder isokinetic rotational strength and throwing accuracy. This was a block counterbalanced, crossover, repeated measures study design utilizing 20 individuals without self-reported shoulder or cervical pathology. Shoulder function was measured with and without experimental pain injection (2 mL of 5% hypertonic saline) in the sub-acromial space. Functional tasks consisted of shoulder rotational strength utilizing isokinetic testing and throwing accuracy via the functional throwing performance index. The hypertonic saline induced moderate pain levels in all participants (4.3-5.1/10). Normalized shoulder internal (t = 3.76, p = 0.001) and external (t = 3.12, p = 0.006) rotation strength were both diminished in the painful condition compared to the pain free condition. Throwing accuracy was also reduced while the participants experienced pain (t = 3.99, p = 0.001). Moderate levels of experimental shoulder pain were sufficient to negatively influence shoulder strength and throwing accuracy in participants without shoulder pathology