Faculty Bibliography

Orishimo, KF, Fukunaga, T, Kremenic, IJ, Rao, S, Magill, R, Ling, WK, McHugh, MP, and Nicholas, SJ. Countermovement jump inefficiency is mostly independent of quadriceps weakness in athletes returning to sport after anterior cruciate ligament reconstruction. J Strength Cond Res XX(X): 000-000, 2024-After anterior cruciate ligament reconstruction (ACLR), comparing ground reaction force (GRF) metrics during countermovement jumps (CMJs) and isokinetic quadriceps strength testing may aid in return-to-sport decision-making. The purpose of this study was to compare asymmetries in GRF metrics during bilateral and unilateral CMJs and asymmetries in quadriceps strength between patients after ACLR and healthy athletes. Twenty-two patients who had undergone ACLR and 12 healthy athletes performed isokinetic tests of quadriceps strength and maximal-effort bilateral and unilateral CMJs on force plates. Countermovement jumps force and isokinetic measurements were compared using repeated-measures analysis of variance. Associations between asymmetries in CMJ metrics and isokinetics were assessed using correlation analysis. In the patients, significant asymmetries in knee extension strength were found (24.5% at 60 °·s-1, 13% at 180 °·s-1). In addition, asymmetries were found in 4 of 6 GRF metrics during bilateral CMJs and in 10 of 15 metrics during unilateral CMJs. The control group showed no significant asymmetries in quadriceps strength or CMJ GRF metrics. Asymmetry in knee extension strength was not correlated with any bilateral CMJ asymmetries and only 2 unilateral CMJ asymmetries. Asymmetry in knee extension power was correlated with 3 bilateral CMJ asymmetries and 3 unilateral CMJ asymmetries. A comparison of GRF profiles revealed functional deficits on the involved side of the patients during both CMJs, indicating difficulty with stretch-shortening cycle function. Asymmetries were partially explained by deficits in quadriceps power but mostly independent of quadriceps weakness. Return-to-sport assessments after ACLR should include the assessment of the biomechanical efficiency of lower extremity stretch-shortening cycle function.

Persons with blindness and low vision experience increased fall and injury risk beyond atypical biomechanics and balance impairments. Falling risk doubles with blindness, and more than triples with depth perception losses. Despite this, physical therapy focuses on musculoskeletal injuries postevent rather than taking a proactive and preventative approach for persons with blindness and low vision. We posit that physical therapy implemented preinjury, alongside orientation and mobility training of adapted movement protocols could positively affect injury avoidance and severity for persons with blindness and low vision. The global VISION 2020 initiative seeks increased access to rehabilitation services and treatments to enhance quality-of-life for persons with blindness and low vision. In support, this article reviews research studies in rehabilitation science that promote physical health and well-being, and stresses preventative skilled mobility and therapeutic exercise to mitigate injury. To reduce the personal, financial, and societal costs associated with blindness and low vision, as well as position patients for better outcomes, we review an evidence base that may generate immediate impact in this area. While these recommendations provide an initial framework, the role of physical therapy in prehabilitative care remains a critical gap that must be addressed. It is imperative that interventions, guidelines, impairment/severity-specific practices, and overall health promotion are re-evaluated and redesigned for persons with blindness and low vision, affording equity for health and mobility.

We compared the magnitude of exercise-induced hypoalgesia and conditioned pain modulation between blood-flow restriction (BFR) resistance exercise (RE) and moderate-intensity RE. Twenty-five asymptomatic participants performed unilateral leg press in two visits. For moderate-intensity RE, subjects exercised at 50% 1RM without BFR, whereas BFR RE exercised at 30% 1RM with a cuff inflated to 60% limb occlusion pressure. Exercise-induced hypoalgesia was quantified by pressure pain threshold changes before and after RE. Conditioned pain modulation was tested using cold water as the conditioning stimulus and mechanical pressure as the test stimulus and quantified as pressure pain threshold change. Difference in conditioned pain modulation pre- to post-RE was then calculated. The differences of RE on pain modulations were compared using paired t-tests. Pearson's r was used to examine the correlation between exercise-induced hypoalgesia and changes in conditioned pain modulation. We found greater hypoalgesia with BFR RE compared to moderate-intensity RE (p=0.008). Significant moderate correlations were found between exercise-induced hypoalgesia and changes in conditioned pain modulation (BFR: r=0.63, moderate-intensity: r=0.72). BFR RE has favorable effects on pain modulation in healthy adults and the magnitude of exercise-induced hypoalgesia is positively correlated with conditioned pain modulation activation.

This study assessed muscle activity (root mean square, RMS, and median frequency, MDF) to evaluate the acute response to blood flow restriction (BFR) resistance exercise (RE) and conventional moderate intensity (MI) RE. We also performed exploratory analyses of differences based on sex and exercise-induced hypoalgesia (EIH). Fourteen asymptomatic individuals performed four sets of unilateral leg press with their dominant leg to volitional fatigue under two exercise conditions: BFR RE and MI RE. Dominant side rectus femoris (RF) and vastus lateralis (VL) muscle activity were measured using surface electromyography (sEMG) through exercise. RMS and MDF were calculated and compared between conditions and timepoints using a linear mixed model. Pressure pain thresholds (PPT) were tested before and immediately after exercise and used to quantify EIH. Participants were then divided into EIH responders and nonresponders, and the differences on RMS and MDF were compared between the two groups using Hedges' g. RMS significantly increased over time (RF: p = 0.0039; VL: p = 0.001) but not between conditions (RF: p = 0.4; VL: p = 0.67). MDF decreased over time (RF: p = 0.042; VL: p < 0.001) but not between conditions (RF: p = 0.74; VL: p = 0.77). Consistently lower muscle activation was found in females compared with males (BRF, RF: g = 0.63; VL, g = 0.5. MI, RF: g = 0.72; VL: g = 1.56), with more heterogeneous findings in MDF changes. For BFR, EIH responders showed greater RMS changes (Δ RMS) (RF: g = 0.90; VL: g = 1.21) but similar MDF changes (Δ MDF) (RF: g = 0.45; VL: g = 0.28) compared to nonresponders. For MI, EIH responders demonstrated greater increase on Δ RMS (g = 0.61) and decrease on Δ MDF (g = 0.68) in RF but similar changes in VL (Δ RMS: g = 0.40; Δ MDF: g = 0.39). These results indicate that when exercising to fatigue, no statistically significant difference was observed between BFR RE and conventional MI RE in Δ RMS and Δ MDF. Lower muscle activity was noticed in females. While exercising to volitional fatigue, muscle activity may contribute to EIH.

Research documents racial disparities in chronic low back pain (CLBP). Few studies have examined racial disparities in movement-related appraisals and no studies have examined anticipatory appraisals prior to or pain behaviors during functional activities among individuals with CLBP. This cross-sectional study examined racial differences in anticipatory appraisals of pain, concerns about harm, and anxiety, appraisals of pain and anxiety during movement, and observed pain behaviors during three activities of daily living (supine-to-standing bed task, sitting-to-standing chair task, floor-to-waist lifting task) in a sample (N = 126) of non-Hispanic Black (31.0%), Hispanic (30.2%), and non-Hispanic White (38.9%) individuals with CLBP. Hispanic participants reported more expected pain, concerns about harm, and pre-movement anxiety prior to the bed and chair tasks compared to non-Hispanic White participants. Hispanic participants reported more pain during the bed task and more anxiety during the bed and chair tasks compared to non-Hispanic White participants. Non-Hispanic Black participants reported more expected pain, concerns about harm, and pre-movement anxiety prior to the bed task and more pre-movement anxiety prior to the chair task compared to non-Hispanic White participants. Non-Hispanic Black participants reported more anxiety during the bed and chair tasks compared to non-Hispanic White participants. Non-Hispanic Black participants were observed to have significantly more verbalizations of pain during the bed task compared to non-Hispanic White participants. Current findings identify racial disparities in important cognitive-behavioral and fear-avoidance mechanisms of pain. Results indicate a need to revisit traditional theoretical and treatment models in CLBP, ensuring racial disparities in pain cognitions are considered. PERSPECTIVE: This study examined racial disparities in anticipatory and movement-related appraisals, and pain behaviors during activities of daily living among Non-Hispanic Black, Non-Hispanic White, and Hispanic individuals with CLBP. Racial disparities identified in the current study have potentially important theoretical implications surrounding cognitive-behavioral and fear-avoidance mechanisms of pain.

PURPOSE:To compare the effects of enhanced and limited patient-clinician relationships during patient history taking on objective functional measures and pain appraisals for individuals with chronic low back pain (CLBP). METHODS:Fifty-two (52) participants with CLBP, unaware of the two groups, were randomized using concealed allocation to an enhanced (n=26) or limited (n=26) patient-clinician relationship condition. Participants shared their history of CLBP with a clinician who enacted either enhanced or limited communication strategies. Fingertip-to-floor, one-minute lift, and Biering-Sorensen tests, and visual analogue scale for pain at rest were assessed before and after the patient-clinician relationship conditions. FINDINGS:The enhanced condition resulted in significantly greater improvements in the one-minute lift test (F(1,49)=7.47, p&lt;.01, ηp2=0.13) and pain at rest (F(1,46)=4.63, p=.04, ηp2=0.09), but not the fingertip-to-floor or Biering-Sorensen tests, compared with the limited group. CONCLUSIONS:Even without physical treatment, differences in patient-clinician relationships acutely affected lifting performance and pain among individuals with CLBP.

OBJECTIVE:Investigate if integrated exercise and psychosocial (EP) interventions effect self-efficacy to manage pain and self-efficacy for physical functioning compared to alternate interventions, usual care, waitlists and attention controls for individuals with chronic low back pain (CLBP). METHODS:MEDLINE, Embase, CINAHL, Web of Science, PsychINFO, PEDro, and Cochrane Library were searched. Included randomized controlled trials utilized an EP intervention for CLBP and measured self-efficacy. Independent reviewers screened abstracts, reviewed full-texts, extracted data, and assessed risk of bias. GRADE, synthesis without meta-analysis, and ranges of effects (Hedges' g) were used. RESULTS:2207 Participants were included (22-studies). EP interventions positively effected self-efficacy to manage pain short-term compared to usual care (range of effects: -0.02, 0.94) and controls (range of effects: 0.69, 0.80) and intermediately compared to usual care (range of effects: 0.11, 0.29); however, no differences were found when compared to alternate interventions. EP interventions positively effected self-efficacy for physical functioning short-term compared to alternate interventions (range of effects: 0.57, 0.71), usual care (range of effects: -0.15, 0.94), and controls (range of effects: 0.31, 0.56), and intermediately compared to alternate interventions (1-study, effect: 0.57) and controls (1-study, effect: 0.56). Conclusions were limited by low to very low-quality-evidence often from risk of bias, imprecision, and clinical/statistical heterogeneity. CONCLUSIONS:EP interventions may be more effective short-term for self-efficacy to manage pain than usual care and waitlists, but not alternate interventions. EP interventions may be effective for self-efficacy for physical functioning at short- and intermediate-term compared to alternate interventions, usual care, waitlist and attention controls. Considerations for future research include methods for blinding and measurement of self-efficacy for physical functioning.

Characterization of fatigue using surface electromyography (sEMG) data has been motivated for rehabilitation and injury-preventative technologies. Current sEMG-based models of fatigue are limited due to (a) linear and parametric assumptions, (b) lack of a holistic neurophysiological view, and (c) complex and heterogeneous responses. This paper proposes and validates a data-driven non-parametric functional muscle network analysis to reliably characterize fatigue-related changes in synergistic muscle coordination and distribution of neural drive at the peripheral level. The proposed approach was tested on data collected in this study from the lower extremities of 26 asymptomatic volunteers (13 subjects were assigned to the fatigue intervention group, and 13 age/gender-matched subjects were assigned to the control group). Volitional fatigue was induced in the intervention group by moderate-intensity unilateral leg press exercises. The proposed non-parametric functional muscle network demonstrated a consistent decrease in connectivity after the fatigue intervention, as indicated by network degree, weighted clustering coefficient (WCC), and global efficiency. The graph metrics displayed consistent and significant decreases at the group level, individual subject level, and individual muscle level. For the first time, this paper proposed a non-parametric functional muscle network and highlighted the corresponding potential as a sensitive biomarker of fatigue with superior performance to conventional spectrotemporal measures.

The purpose of this study was to test the feasibility and safety of High-Level Mobility (HLM) training on adults with Acquired Brain Injury (ABI). Our hypotheses were that HLM training would be feasible and safe. This study was a pilot randomized control trial with a Simple Skill Group (SSG) and a Complex Skill Group (CSG). Both groups received 12 sessions over 8 weeks and completed 4 testing sessions over 16 weeks. The SSG focused on locomotion, while CSG focused on the acquisition of running. Feasibility was assessed in terms of process, resources, management, and scientific metrics, including safety. Among the 41 participants meeting inclusion criteria, 28 consented (CSG, n = 13, SSG, n = 15), 20 completed the assigned protocol and 8 withdrew (CSG n = 4, SSG n = 4). Adherence rate to assigned protocol was 100%. There were two Adverse Events (AEs), 1 over 142 SSG sessions and 1 over 120 CSG sessions. The AE Odd Ratio (OR) (CSG:SSG) was 1.18 (95% CI: 0.07, 19.15). The data support our hypotheses that HLM training is feasible and safe on ambulatory adults with ABI.