Clinical Scenario: Ulnar collateral ligament injuries are common in baseball pitchers, with excessive elbow varus torque linked to medial elbow injuries. Trunk tilt, or motion in the frontal plane, could be an identifiable and modifiable factor in medial elbow loading. Clinical Question: In high school through professional baseball pitchers, how does increased contralateral trunk tilt compared with no/limited contralateral trunk tilt influence elbow varus torque? Summary of Key Findings: Four studies were included: all were labeled as “controlled” or “descriptive laboratory studies,” representing cross-sectional observational analytic design. One study compared biomechanics of professional pitchers with and without ulnar collateral ligament reconstruction. Two studies measured biomechanics in college pitchers, one of which also included simulations of joint angles. The fourth study measured biomechanics of high school pitchers. All studies measured trunk tilt and its relationship to elbow varus torque, with 3 of the studies linking increased contralateral trunk tilt with increased elbow varus torque. Clinical Bottom Line: Moderate evidence indicated as contralateral trunk tilt increased, so did elbow varus torque, indicating trunk tilt may be a modifiable factor to decrease medial elbow loading during pitching. Strength of Recommendation: Majority consistent findings from the level 3 cross-sectional observational analytic designs suggest grade B evidence in support of trunk tilt as a factor in increasing elbow varus torque.
Sierra Hakanson, Samuel T. Johnson, Emily C. Norcross, and Cathleen N. Brown
Kyndell R. Crowell, Ryan D. Nokes, and Nicole L. Cosby
Clinical Scenario: Dynamic knee valgus (DKV) is a mechanical alteration in the knee that leads to increased risk of injury. Weakness of hip musculature in hip abduction (HABD), extension (HEXT), and external rotation (HER) may contribute to increased DKV in single-leg landing tasks. Focused Clinical Question: Is decreased hip strength associated with an increase in DKV during a single-leg landing task in collegiate female athletes? Summary of Key Findings: Three studies were included: One randomized control trial (RCT), one cohort study, and one case-control. All three studies found that decreases in HABD and HER strength contributed to increased DKV during single-leg landing tasks. One study also found that the hip extensors contribute to controlling hip adduction, a common factor in many mechanisms of injuries. These three studies recommended strengthening HABD, HEXT, and HER to decrease DKV and reduce the risk of injury at the knee. Clinical Bottom Line: Weak HABD, HEXT, and HER contribute to increased DKV in college female athletes, but strengthening HABD, HEXT, and HER can lead to decreases in DKV and, overall, reduce the risk of injury at the knee. Strength of Recommendation: These articles were graded with a level of evidence of III or higher, giving a grade of B strength of recommendation that weak HABD, HEXT, and HER are associated with increased DKV in collegiate female athletes.
Jessica Murphy, Karen A. Patte, Philip Sullivan, and Scott T. Leatherdale
The mental health benefits of physical activity may relate more to the context of the behavior, rather than the behavior of being active itself. The association between varsity sport (VS) participation, depression, and anxiety symptoms was explored using data from 70,449 high school students from the Cannabis use, Obesity, Mental health, Physical activity, Alcohol use, Smoking, and Sedentary behavior study. The model adjusted for potential covariates; interactions by sex and participation in outside of school sport (OSS) were explored. Overall, 70% and 24% of respondents met or exceeded cutoff values for depression and anxiety, respectively. Students participating in VS had lower symptoms of anxiety and depression compared with nonparticipants. Results were consistent regardless of OSS participation; associations were strongest among students who participated in both VS and OSS and males. Participation in VS may prove beneficial for the prevention and/or management of depression or anxiety symptoms, particularly among males. An additive beneficial effect of OSS on depression and anxiety scores may exist.
Michael W. Kirkwood, David R. Howell, Brian L. Brooks, Julie C. Wilson, and William P. Meehan III
While placebo effects are well recognized within clinical medicine, “nocebo effects” have received much less attention. Nocebo effects are problems caused by negative expectations derived from information or treatment provided during a clinical interaction. In this review, we examine how nocebo effects may arise following pediatric concussion and how they may worsen symptoms or prolong recovery. We offer several suggestions to prevent, lessen, or eliminate such effects. We provide recommendations for clinicians in the following areas: terminology selection, explicit and implicit messaging to patients, evidence-based recommendations, and awareness of potential biases during clinical interactions. Clinicians should consider the empirically grounded suggestions when approaching the care of pediatric patients with concussion.
Jamon Couch, Marc Sayers, and Tania Pizzari
Context: An imbalance between shoulder internal rotation (IR) and external rotation (ER) strength in athletes is proposed to increase the risk of sustaining a shoulder injury. Hand-held (HHD) and externally fixed dynamometry are reliable forms of assessing shoulder IR and ER strength. A new externally fixed device with an attachable fixed upper-limb mold (The ForceFrame) exists; however, its reliability in measuring shoulder strength is yet to be investigated. Objective: To determine the test–retest reliability of the ForceFrame, with and without the fixed upper-limb mold, in the assessment of shoulder IR and ER strength, as compared with HHD. Design: Test–retest reliability study. Setting: Laboratory, clinical. Participants: Twenty-two healthy and active individuals were recruited from the university community and a private physiotherapy practice. Main Outcome Measures: Maximal isometric shoulder IR and ER strength was measured using the ForceFrame and traditional HHD in neutral and at 90° shoulder abduction. Mean (SD) strength measures were calculated. Test–retest reliability was analyzed using intraclass correlation coefficients (3, 1). The SEM and minimal detectable change were calculated. Results: Good to excellent test–retest reliability was found for all shoulder strength tests across HDD and ForceFrame dynamometry (intraclass correlation coefficients [3, 1] = .854–.916). The minimal detectable changes ranged between 25.61 and 41.84 N across tests. Test–retest reliability was not affected by the dynamometer or testing position. Conclusions: The results from this study indicate that both the ForceFrame and HHD are suitable for measuring shoulder strength in clinical practice. The use of the fixed upper-limb mold with the ForceFrame does not improve reliability.
Nickolai J.P. Martonick, Ashley J. Reeves, James A. Whitlock, Taylor C. Stevenson, Scott W. Cheatham, Craig P. McGowan, and Russell T. Baker
Context: Instrument-assisted Soft Tissue Mobilization (IASTM) is a therapeutic intervention used by clinicians to identify and treat myofascial dysfunction or pathology. However, little is known about the amount of force used by clinicians during an IASTM treatment and how it compares to reports of force in the current literature. Objective: To quantify the range of force applied by trained clinicians during a simulated IASTM treatment scenario. Design: Experimental. Setting: University research laboratory. Participants: Eleven licensed clinicians (physical therapist = 2, chiropractor = 2, and athletic trainer = 7) with professional IASTM training participated in the study. The participants reported a range of credentialed experience from 1 to 15 years (mean = 7 [4.7] y; median = 6 y). Intervention: Participants performed 15 one-handed unidirectional sweeping strokes with each of the 5 instruments for a total of 75 data points each. Force data were collected from a force plate with an attached skin simulant during a hypothetical treatment scenario. Main Outcome Measures: Peak force and average forces for individual strokes across all instruments were identified. Averages for these forces were calculated for all participants combined, as well as for individual participants. Results: The average of peak forces produced by our sample of trained clinicians was 6.7 N and the average mean forces was 4.5 N. Across individual clinicians, average peak forces ranged from 2.6 to 14.0 N, and average mean forces ranged from 1.6 to 10.0 N. Conclusions: The clinicians in our study produced a broad range of IASTM forces. The observed forces in our study were similar to those reported in prior research examining an IASTM treatment to the gastrocnemius of healthy individuals and greater than what has been reported as effective in treating delayed onset muscle soreness. Our data can be used by researchers examining clinically relevant IASTM treatment force on patient outcomes.
Gabriel dos Santos Oliveira, João Breno de Araujo Ribeiro-Alvares, Felipe Xavier de Lima-e-Silva, Rodrigo Rodrigues, Marco Aurélio Vaz, and Bruno Manfredini Baroni
Context: Eccentric knee flexor strength assessments have a key role in both prevention and rehabilitation of hamstring strain injuries. Objective: To verify the reliability of a clinical test for measuring eccentric knee flexor strength during the Nordic hamstring exercise using a commercially available handheld dynamometer. Design: Reliability study. Setting: Physical Therapy Laboratory, Federal University of Health Sciences of Porto Alegre (Brazil). Participants: Fifty male amateur athletes (soccer or rugby players; 24  y). Main Outcome Measures: Eccentric knee flexor strength. Results: When compared with a load cell–based device, the clinical test using a handheld dynamometer provided smaller force values (P < .05) with large effect sizes (.92–1.21), moderate intraclass correlation (.60–.62), typical error of 30 to 31 N, and coefficient of variation of 10% to 11%. Regarding the test–retest reproducibility (2 sessions separated by 1 week), the clinical test provided similar force values (P > .05) with only small effect sizes (.20–.27), moderate to good correlation (.67–.76), typical error of 23 to 24 N, and coefficient of variation of 9% to 10%. Conclusion: The clinical test with handheld dynamometer proposed by this study can be considered an affordable and relatively reliable tool for eccentric knee flexor strength assessment in the clinical setting, but results should not be directly compared with those provided by load cell–based devices.
Aaron Byrne, Clare Lodge, and Jennifer Wallace
Context: Single-leg stability has been associated with injury risk and is a key component of many injury prevention interventions. Methods of measuring single-leg stability are varied yet often unreliable. Objective: To establish within- and between-day test–retest reliability for single-leg time to stabilization (SL-TTS) following a drop-landing maneuver of 20 cm in height among a healthy cohort. Design: Test–retest reliability study. Setting: Healthy cohort from a third-level educational institution. Participants: Nineteen (11 females and 8 males) healthy individuals. Main Outcome Measures: The SL-TTS in the vertical plane. Results: The SL-TTS showed good within-day (intraclass correlation coefficient = .715) and excellent between-day (intraclass correlation coefficient = .83) test–retest reliability. The minimal detectable change was calculated as 171.6 ms for within-day contexts and 123.8 ms for between-day contexts. Conclusions: This method of measuring SL-TTS is reliable and could be used to detect changes over time in a healthy cohort. This could be of value to clinicians in injury risk factor identification or assessing the effectiveness of single-leg stability training. However, further research is needed to investigate its reliability in pathological populations.
Jennifer L. Ostrowski, Alexa Beaumont, and Emily Dochterman
Clinical Scenario: Pathologies of the long head of the biceps brachii (LHB) tendon are a source of shoulder pain in many people. It is important to have a reliable assessment of the LHB tendon to make an accurate diagnosis and provide the correct treatment or referral if necessary. Shoulder ultrasound is very accurate in the diagnosis of rotator cuff tears. However, its ability to detect pathologies of the LHB tendon is still unclear. Clinical Question: In patients with shoulder pain, can musculoskeletal ultrasound accurately diagnose LHB tendon pathologies? Summary of Key Findings: Four high-quality cohort studies met inclusion criteria and were included in the critical appraisal. The STrengthening the Reporting of OBservational studies in Epidemiology checklist was used to score the articles on methodology and consistency. Three studies evaluated accuracy in diagnosis of full-thickness tears and found high sensitivity (SN) and specificity (SP). Three studies evaluated accuracy in diagnosis of partial-thickness tears and found low SN and negative predictive value, but high SP and positive predictive value. Two studies evaluated tendon subluxation/dislocation and found high SN and SP. Two studies evaluated tendinitis and found moderate SN and high SP. Clinical Bottom Line: There is moderate to strong evidence to support the use of musculoskeletal ultrasound in diagnosis of LHB tendon pathology. Strength of Recommendation: There is grade B evidence that musculoskeletal ultrasound can accurately diagnose full-thickness tears and tendon subluxation/dislocation; can rule in partial-thickness tears (based on SP and positive predictive value), but not rule out partial-thickness tears; and can rule in tendinitis (based on SP and positive predictive value), but not rule out tendinitis.
Félix Croteau, Shawn M. Robbins, and David Pearsall
Context: Previous authors suggest that lack of strength is an important risk factor for injuries in water polo. Hand-held dynamometers have potential as a clinical tool to measure strength, but they have not been validated in water polo players. Objective: The purpose of this study was to estimate intertrial variability and concurrent validity of hand-held dynamometer shoulder strength measurements in elite water polo players. Methods: A total of 19 male and 20 female elite water polo players performed isometric external (ER) and internal (IR) rotation strength tests against a hand-held dynamometer bilaterally in supine position with the shoulder in a 90–90 position. In addition, concentric IR and ER was captured at 90 deg/s with an isokinetic dynamometer, and torque values were determined near the 90–90 position. Main Outcome Measures: Spearman correlation coefficients were calculated for ER torque, IR torque, and ER/IR ratios between the devices. Two-way mixed-model intraclass correlations were used to assess intertrial variability. Results: Correlations between the devices were strong to very strong (ρ = .65–.82, P < .01) for absolute IR and ER but low for ER/IR ratios (ρ = .29, P = .07). There was less agreement at higher torque values. Intertrial variability was low with intraclass correlation values .88 to .93, P < .05. Conclusions: These results show that hand-held dynamometers are adequate clinical alternatives to measure absolute shoulder strength in water polo players. Stronger players may require stronger evaluators to resist the player’s push and obtain reliable results.