Bradley S. Davidson

The forces applied during a spinal manipulation produce a neuromuscular response in the paraspinal muscles. A systematic evaluation of the factors involved in producing this muscle activity provides a clinical insight. The purpose of this study is to quantify the effect of treatment factors (manipulation sequence and manipulation site) and response factors (muscle layer, muscle location, and muscle side) on the neuromuscular response to spinal manipulation. The surface and indwelling electromyographies of 8 muscle sites were recorded during lumbar side-lying manipulations in 20 asymptomatic participants. The effects of the factors on the number of muscle responses and the muscle activity onset delays were compared using mixed-model linear regressions, effect sizes, and equivalence testing. The treatment factors did not reveal statistical differences between the manipulation sequences (first or second) or manipulation sites (L3 or SI) in the number of muscle responses (p = 0.11, p = 0.28, respectively), or in muscle activity onset delays (p = 0.35 p = 0.35, respectively). There were significantly shorter muscle activity onset delays in the multifidi compared to the superficial muscles (p = 0.02). A small effect size of side (d = 0.44) was observed with significantly greater number of responses (p = 0.02) and shorter muscle activity onset delays (p < 0.001) in the muscles on the left side compared to the right. The location, layer, and side of the neuromuscular responses revealed trends of decreasing muscle response rates and increasing muscle activity onset delays as the distance from the manipulation site increased. These results build on the body of work suggesting that the specificity of manipulation site may not play a role in the neuromuscular response to spinal manipulation—at least within the lumbar spine. In addition, these results demonstrate that multiple manipulations performed in similar areas (L3 and S1) do not change the response significantly, as well as contribute to the clinical understanding that the muscle response rate is higher and with a shorter delay, the closer it is to the manipulation.

Introduction Despite first coming into view over two years ago, effective diagnostic and treatment pathways for Long COVID continue to evade the medical community. The overlap in neurological-based symptoms and neuroinflammatory origin indicates that the framework of post-concussion syndrome may provide insight into new diagnostics and treatment for patients with Long COVID. The objective of this investigation was to determine whether tools from the four common domains of concussion assessment were sensitive to differentiate between patients with Long COVID from a reference group who was infected with Sars-CoV-2 and does not have Long COVID. Methods In this prospective cohort design, each participant self reported their group (Acute, n=28) and Long COVID Group (n=33). Each participant underwent an examination in four assessment categories: symptoms, vestibular nystagmography, Automated Neuropsychological Assessment Metrics (ANAM), and a series of balance tasks. Results Total Symptom scores were separated into functional classifications and showed clear success as a tool to differentiate between Acute and Long COVID. Five of the 33 people in the Long COVID had detectable central lesions, which increases the risk of developing long COVID by 64% (Relative Risk=1.64). A wide variety of objective and quantitative measures from post-concussion care are sensitive to the Long COVID condition. Prolonged latency during random saccades eye tracking was present (pDiscussion Our results indicate that long-standing and validated post-concussion symptom questionnaires may be used for quantifying the severity of Long COVID. Some of the most sensitive measures (especially the King-Devick rapid reading test) are easy to implement clinically and may be effective at tracking patient progress in the context of Long COVID treatment. The results point to wide deficits in motor integration and provide a rationale for treating the subset of Long COVID patients with similar rehabilitation strategies as patients with post-concussion syndrome.

The objective of this research was to determine if three alternative shoe closures improve biomechanical performance measures compared to a standard lace closure in agility-based movements. NCAA Division 1 and club-level male athletes recruited from lacrosse, soccer, tennis, and rugby performed four court-based movements: Lateral Skater Jump Repeats (LSJ), Countermovement Jump Repeats (CMJ), Triangle Drop Step Drill (TDS), and Anterior-Posterior Drill (AP). Each athlete performed the movements in four shoe upper closures: Standard Closure, Lace Replacement, Y Wrap, and Tri Panel. Movement completion time, Ground contact time, peak eccentric rate of force development (RFD), peak concentric GRF, peak concentric COM power, eccentric work, and concentric work were measured. The Y Wrap configuration the Tri Panel configuration delivered improvements between 3 and 9% over the Standard Closure depending on the movement tested and variable of interest. The Lace Replacement had mixed results with some improvements and some declines in performance. This study allowed for the mechanical properties of the shoe bottom package to remain consistent across designs to examine if alternative upper configurations could enhance performance. We hypothesise that improved containment and possibly increased proprioception—due to the wrapping fit of the configurations influences these changes in performance. These findings suggest that the design and construction shoe upper is essential to consider in athletic shoe design.

Quantitative assessments of patient movement quality in osteoarthritis (OA), specifically spatiotemporal gait parameters (STGPs), can provide in-depth insight into gait patterns, activity types, and changes in mobility after total knee arthroplasty (TKA). A study was conducted to benchmark the ability of multiple deep neural network (DNN) architectures to predict 12 STGPs from inertial measurement unit (IMU) data and to identify an optimal sensor combination, which has yet to be studied for OA and TKA subjects. DNNs were trained using movement data from 29 subjects, walking at slow, normal, and fast paces and evaluated with cross-fold validation over the subjects. Optimal sensor locations were determined by comparing prediction accuracy with 15 IMU configurations (pelvis, thigh, shank, and feet). Percent error across the 12 STGPs ranged from 2.1% (stride time) to 73.7% (toe-out angle) and overall was more accurate in temporal parameters than spatial parameters. The most and least accurate sensor combinations were feet-thighs and singular pelvis, respectively. DNNs showed promising results in predicting STGPs for OA and TKA subjects based on signals from IMU sensors and overcomes the dependency on sensor locations that can hinder the design of patient monitoring systems for clinical application.

Objective: In this study we examined the temporal stability of the Immediate Post-Concussion Assessment and Cognitive Test (ImPACT) within NCAA Division I athletes across various timepoints using an exhaustive series of statistical models. Methods: Within a cohort design, 48 athletes completed repeated baseline ImPACT assessments at various timepoints. Intraclass correlation coefficients (ICC) were calculated using a two-way mixed effects model with absolute agreement. Results: Four ImPACT composite scores (Verbal Memory, Visual Memory, Visual Motor Speed, and Reaction Time) demonstrated moderate reliability (ICC = 0.51–0.66) across the span of a typical Division I athlete’s career, which is below previous reliability recommendations (0.90) for measures used in individual decision-making. No evidence of fixed bias was detected within Verbal Memory, Visual Motor Speed, or Reaction Time composite scores, and minimal detectable change values exceeded the limits of agreement. Conclusions: The demonstrated temporal stability of the ImPACT falls below the published recommendations, and as such, fails to provide robust support for the NCAA’s recommendation to obtain a single preparticipation cognitive baseline for use in sports-related concussion management throughout an athlete’s career. Clinical interpretation guidelines are provided for clinicians who utilize baseline ImPACT scores for later performance comparisons.

Sport-related concussion return to play (RTP) decisions are largely based on the resolution of self-reported symptoms and neurocognitive function. Some evaluators also incorporate balance; however, an objective approach to balance that can detect effects beyond the acute condition is warranted. The purpose of this study is to examine linear measures of biomechanical balance up to 6 months post-concussion, and to present preliminary diagnostic thresholds useful for RTP. Each concussed athlete participated in instrumented standing balance tasks at 4 timepoints post-concussion. The measures from concussed athletes were compared to the sport-matched non-concussed athlete group at each timepoint. Centre of pressure (COP) mediolateral (ML) velocity in double-leg stance on a hard surface discriminated well between non-concussed and concussed athletes. COP anterior-posterior (AP) velocity in tandem stance on foam showed sensitivity to concussion. Sixty per cent of athletes at 6 months post-concussion did not recover to within the proposed COP ML velocity threshold in double-leg stance on a hard surface. Seventy-one per cent of athletes at 6 months post-concussion did not recover to within the COP AP velocity threshold in tandem stance on foam. This lack of recovery potentially indicates vestibular and motor control impairments long past the typical period of RTP.

Objectives: This study compares people with recurrent low back pain (rLBP) and people with pre-clinical low back pain (standing-induced low back pain developers; PDs) to each other and back-healthy controls (non-pain developers; NPDs). Movement variability and muscular co-activity related to coordination are important for both rLBP and PDs, and these two groups also have altered static spine extension. Methods: Eleven participants with recurrent low back pain, and twenty-one asymptomatic participants, categorized as PDs (11) and NPDs (10) through an established standing protocol, volunteered for this study. Three phases of standing extension motion (lean, hold, and return to neutral) were analyzed. Root mean square angular jerk was calculated from trunk and pelvis kinematics, co-activation of the trunk and hip musculature were assessed in four-muscle sets. Results: Root-mean-square jerk was greater when returning to neutral than when leaning back during standing extension in all three groups. People with rLBP had reduced co-activity in their trunk extensors, people classified as PD had more co-activity in their hip extensors compared with the other groups, and anterior trunk co-activity was phase-dependent, and similar between groups. Discussion: Movement control alterations with low back pain may start as an over-protective co-activation strategy in those with standing-induced LBP and progress to an under-protective strategy in those with recurrent low back pain. Level of Evidence: 3.