Reactive postural responses predict risk for acute musculoskeletal injury in collegiate athletes.

Identifying risk factors for musculoskeletal injury is critical to maintain the health and safety of athletes. While current tests consider isolated assessments of function or subjective ratings, objective tests of reactive postural responses, especially when in cognitively demanding scenarios, may better identify risk of musculoskeletal injury than traditional tests alone. OBJECTIVES: Examine if objective assessments of reactive postural responses, quantified using wearable inertial measurement units, are associated with the risk for acute lower extremity musculoskeletal injuries in collegiate athletes. DESIGN: Prospective survival analysis. METHODS: 191 Division I National Collegiate Athletic Association athletes completed an instrumented version of a modified Push and Release (I-mP&R) test at the beginning of their competitive season. The I-mP&R was performed with eyes closed under single- and dual-task (concurrent cognitive task) conditions. Inertial measurement units recorded acceleration and angular velocity data that was used to calculate time-to-stability. Acute lower extremity musculoskeletal injuries were tracked from first team activity for six months. Cox proportional hazard models were used to determine if longer times to stability were associated with faster time to injury. RESULTS: Longer time-to-stability was associated with increased risk of injury; every 250 ms increase in dual-task median time-to-stability was associated with a 36% increased risk of acute, lower-extremity musculoskeletal injury. CONCLUSIONS: Tests of reactive balance, particularly under dual-task conditions, may be able to identify athletes most at risk of acute lower extremity musculoskeletal injury. Clinically-feasible, instrumented tests of reactive should be considered in assessments for prediction and mitigation of musculoskeletal injury in collegiate athletes.

Prospective Evaluation of Pain Flares and Time Until Pain Relief Following Musculoskeletal Corticosteroid Injections.

BACKGROUND: Corticosteroid injections are used ubiquitously within musculoskeletal medicine. One of the most common side effects is a postinjection pain flare, though little is known regarding this phenomenon. HYPOTHESIS: Some risk factors are related to postinjection pain flare following an ultrasound-guided corticosteroid injection. STUDY DESIGN: Prospective clinical research study. LEVEL OF EVIDENCE: Level 2. METHODS: Patients undergoing ultrasound-guided corticosteroid injections in an academic orthopaedic and sports medicine clinic were approached to participate. Patients completed a survey immediately following their injection and again 2 weeks later, asking them about their pain and side effects. A postinjection pain flare was defined as an increase in pain, as defined by the patient. RESULTS: A total of 140 patients completed the entirety of the study, with 29 (20.7%) patients reporting a flare of pain. There was a significant effect of younger age on the development of a pain flare after the injection, estimated as 5.5% decreased odds of developing a flare per year of age (P < 0.01). Gender, injection location, body mass index (BMI), preinjection pain, and corticosteroid type had no contributing effect. When patients obtained relief following the corticosteroid injection, 60.4% had improved pain within 3 days, whereas over 93.7% obtained relief within a week. CONCLUSION: Pain flares seem to affect approximately 1 in 5 patients. With increasing age, the likelihood of postinjection pain flare becomes less likely. Sex, injection location, BMI, preinjection pain, and corticosteroid type do not seem to significantly relate to an increase in pain following injection. CLINICAL RELEVANCE: Corticosteroid injections are common procedures in the orthopaedic and sports medicine settings. Younger patients can be counseled on the higher likelihood of a pain flare following a corticosteroid injection.

Does Anesthetic Relief Correspond to Future Pain Relief?: A Prospective Trial Examining Future Pain Relief for Ultrasound-Guided Corticosteroid-Anesthetic Injections.

OBJECTIVES: The aim of the study was to prospectively evaluate the association between immediate pain relief from injections of local anesthetic with corticosteroid and subsequent pain relief up to 3 mos. The secondary aim was to examine the time until subjective pain relief after these injections. DESIGN: This was a single-center, prospective study of patients undergoing ultrasound-guided corticosteroid injections for musculoskeletal pain. Subjects completed follow-up surveys at 2 wks, 1 mo, and 3 mos postinjections. χ 2 tests and sensitivity analysis were used to examine the primary outcome, at least 50% relief from the injection. Regression modeling examined the effects of demographic and injection-related variables on outcome measures. RESULTS: A total of 132 patients were enrolled (55% female, mean age 52 yrs). Response rates were 87.1% at 2 wks and 77.2% at 3 mos. The positive likelihood ratios from 50% initial pain relief ranged from 1.22 to 1.29 at the three time points, whereas the negative likelihood ratios ranged from 0.54 to 0.63. More than 75% of participants reported subjective pain relief by day 4 after injection. CONCLUSIONS: The predictive value of immediate pain relief for subsequent longer-term pain relief from corticosteroid-anesthetic injections is not particularly high. Most patients will obtain pain relief within 4 days of a corticosteroid injection.

Reactive Postural Responses After Mild Traumatic Brain Injury and Their Association With Musculoskeletal Injury Risk in Collegiate Athletes: A Study Protocol.

Background: Deficits in neuromuscular control are widely reported after mild traumatic brain injury (mTBI). These deficits are speculated to contribute to the increased rate of musculoskeletal injuries after mTBI. However, a concrete mechanistic connection between post-mTBI deficits and musculoskeletal injuries has yet to be established. While impairments in some domains of balance control have been linked to musculoskeletal injuries, reactive balance control has received little attention in the mTBI literature, despite the inherent demand of balance recovery in athletics. Our central hypothesis is that the high rate of musculoskeletal injuries after mTBI is in part due to impaired reactive balance control necessary for balance recovery. The purpose of this study is to (1) characterize reactive postural responses to recover balance in athletes with recent mTBI compared to healthy control subjects, (2) determine the extent to which reactive postural responses remain impaired in athletes with recent mTBI who have been cleared to return to play, and (3) determine the relationship between reactive postural responses and acute lower extremity musculoskeletal injuries in a general sample of healthy collegiate athletes. Methods: This two-phase study will take place at the University of Utah in coordination with the University of Utah Athletics Department. Phase 1 will evaluate student-athletes who have sustained mTBI and teammate-matched controls who meet all the inclusion criteria. The participants will be assessed at multiple time points along the return-to-play progress of the athlete with mTBI. The primary outcome will be measures of reactive postural response derived from wearable sensors during the Push and Release (P&R) test. In phase 2, student-athletes will undergo a baseline assessment of postural responses. Acute lower extremity musculoskeletal injuries for each participant will be prospectively tracked for 1 year from the date of first team activity. The primary outcomes will be the measures of reactive postural responses and the time from first team activity to lower extremity injury. Discussion: Results from this study will further our understanding of changes in balance control, across all domains, after mTBI and identify the extent to which postural responses can be used to assess injury risk in collegiate athletes.