Reliability of Smartphone Inclinometry to Measure Upper Cervical Range of Motion.

Context: Assessment of upper cervical range of motion (UCROM) and mobility is commonly performed in the clinical setting for patients suffering from headache, neck pain and vestibular dysfunction. Reliable and reproducible measurement of this motion is often difficult or too expensive to perform in the clinical setting. Smartphone applications, utilizing the device\u27s internal gyroscope, offer an easy and inexpensive means of measuring UCROM, but their reliability has not been reported in the literature. Objective: Assess the reliability of an inclinometer application, installed on two different devices (iPhone6 (IP), Andriod (AN)), to measure UCROM in a healthy population. Design: Two examiners assessed passive UCROM. Each examiner was assigned to a specific smartphone and a repeated measures design consisting of three trials for each examiner-phone was performed. The order of testing was randomized and the examiners were blinded to UCROM measures. Setting: Laboratory Participants: 38 subjects (19F, 19M; 23.8±1.2 yrs) without pain or injury to the neck and spine for at least 3 months. Intervention: Each examiner passively flexed the head fully and then rotated the head fully in one direction then in another. Peak rotation measures were recorded from each smartphone. Three trials were performed for each phone with a 2-minute break between examiners/phones. Main Outcome Measures: Intraclass Correlation Coefficient (ICC) using a two way mixed, absolute agreement model were obtained (1) between each examiner-phone and (2) within each examiner-phone for the measurements in each rotation direction. Results: Inter-phone/examiner reliability comparing average peak and total UCROM for each device were excellent (0.87, 0.81). Intra-phone/examiner reliability, determined across three trials, was also excellent (AN Right Rot. = 0.91, AN Left Rot. 0.96, IP Right Rot. = 0.98, IP Left = 0.95 Rot.). Conclusion: UCROM can be reliably measured using a smartphone inclinometer application

Correlation of Head Impact Exposures to Vestibular Ocular Assessments

CONTEXT: Managing a concussion injury should involve the incorporation of a multi-faceted approach, including a vision assessment. The fronto-parietal circuits and subcortical nuclei are susceptible to trauma from a concussion injury, leading to dysfunction of the vestibular-ocular system. Research investigating the effect of cumulative subconcussive impacts on neurological function is still in its infancy, but repetitive head impacts may result in vestibular system dysfunction. This dysfunction could create visual deficits, pre-disposing the individual to further head trauma. OBJECTIVE: The purpose of this study was to investigate the cumulative effect of subconcussive impacts on minimum perception time, static visual acuity, gaze stability (GST), and dynamic visual acuity (DVA) scores. DESIGN: Prospective cohort. SETTING: Division I University. PATIENTS: 33 Division I men\u27s lacrosse players (19.52 ± 1.20). INTERVENTION(S): Competitive lacrosse season. MAIN OUTCOME MEASURES: At the beginning and end of the season, the players completed a vestibular-ocular reflex assessment, using the inVision™ system by NeuroCom® to assess: perception, static acuity, gaze stability, and dynamic visual acuity. Score differentials were correlated to the head impact exposure data collected via instrumented helmets. RESULTS: A significant correlation was found between change in perception scores and total number of head impacts, (r = 0.54), and between changes in DVA loss scores on the right and maximum rotational acceleration, (r = 0.36). There were no statistical differences were found between pre and post season VOR variables. CONCLUSIONS: Cumulative subconcussive impacts may negatively affect vestibular ocular reflex scores, resulting in decreased visual performance. This decrease in vestibular ocular function may place the athlete at risk of sustaining additional head impacts or other injuries

A Novel Approach to Reducing Workers Compensation Costs in a Multicenter Hospital System

Objective: To evaluate the efficacy of an injury prevention and monitoring program implemented by athletic trainers to reduce workers compensation costs in a hospital system with multiple centers and locations. Methods: A retrospective analysis of workers compensation claims (ie, lost days, light days, and incurred costs) was performed to compare injury data from 2 years before to 2 years after the start of the program. Results: The program significantly reduced the organization\u27s incurred costs by 46.7% (P = 0.031) and light days by 44% (P = 0.022). Lost days were found to decrease by 37%, however, this decrease was not statistically significant (P = 0.078). Conclusions: Athletic trainers, using their knowledge of anatomy, biomechanics, ergonomics, injury management, and rehabilitation, can effectively prevent and reduce workers compensation costs in a multicenter hospital system

Functional Determination of a Cervical Spine Joint Coordinate System via an Optimization Approach

Abstract of conference presentation. Determination of a subject-specific fixed cervical spine joint coordinate system (JCS) is challenging due to several anatomical constraints. Cervical spine motion (flexion/extension, axial rotation, and lateral bending) is the combined contribution from the occipito-atlanto-axial complex and 2ndcervical vertebra through the 1st thoracic vertebra. Additionally, there is a lack of accessible bony landmarks aligning with rotation axes. Several methods of quantifying total cervical spine motion from three-dimensional kinematic data have been previously reported, however, none of the JCS determination methods have utilized an optimization approach. PURPOSE: The purpose of this study was to determine the feasibility and accuracy of a numerical optimization approach in determining subject-specific cervical spine JCS through a series of coordinated movements. METHODS: Twenty-eight participants (15F; 21.4 ± 5.4 yo), free from any musculoskeletal limitations in the cervical spine, granted informed consent and participated in this IRB approved study. While in a seated position, all participants performed the following sequence of ordered head movements representing their full active neck range of motion (ROM): (1) flexion-extension, (2) axial rotation left-right, (3) lateral flexion left-right. Five reflective markers (dia.=12.5mm) were rigidly fixated to the head via a tight fitting elastic band and a 4-marker reflective marker cluster was rigidly fixated to the upper thoracic region. Marker coordinates were measured with an 8-camera three-dimensional motion capture system (Qualisys OQUS 100; 120 Hz) with a residual accuracy \u3c 0.3 mm. All three-dimensional coordinates were filtered with a 4th order Butterworth lowpass filter with cutoff frequency of 25 Hz. A custom MATLAB program utilized a Nelder-Mead simplex optimization routine to determine axes parameters that minimized the difference between the measured joint motion and the actual joint motion. Off-axis angle deviations were computed over the entire ordered movement sequence and for each joint rotation direction respectively. Computed ROMs were compared against published norms from healthy participants [1]. RESULTS: Averaged across all participants and over all rotations, off-axis angle deviations were 8.1±2.5o. Off-axis deviations were smallest for flexion-extension rotations (3.5±2.3o) and largest for lateral bending rotations (14.0±5.1o). Aggregate active ROMs compared favorably to previous reports (Flexion 67.7±12.3o, Extension 68.4±12.3o, Rotation Left 74.7±8.7o, Rotation Right 73.5±6.6o, Lat. Bending Left 47.6±7.8o, Lat. Bending Right 46.4±6.2o) DISCUSSION: Despite anatomical limitations that prevent traditional joint axes determination, the reported methodology adequately fit a set of ordered head motions with an optimized fixed cervical spine joint coordinate system. An advantage of the current methodology is that body fixed reflective markers do not need to align with either the lab-based coordinate system or a segment coordinate system

The Impact of Vocal Task on Voice Acoustics, Effort and Discomfort Following Submandibular Neuromuscular Electrical Stimulation in Healthy Adults

Background: Neuromuscular electrical stimulation (NMES) offers a potential adjuvant to traditional voice therapy for individuals with dysphonia. The type of vocal task to implement in conjunction with electrical stimulation to achieve maximal therapeutic benefit is unknown. The purpose of this study was to elucidate the impact of tasks on voice outcomes. Methods: Nineteen vocally-healthy adult females, between 23 and 27 years of age (Ave: 23.8, SD: 1.13), participated in the study. 15 participants completed all three 30-minute sessions, and four completed at least one session. NMES was paired with three different voice conditions: high-pitched hum, low-pitched hum, and comfortable-pitched hum. Acoustic (average fundamental frequency and loudness; perturbation (jitter, shimmer, noise to harmonic ratio); Cepstral Spectral Index of Dysphonia; pitch range), perceived phonatory effort, and discomfort (delayed onset muscle soreness) measures were compared across conditions. Results: Eight participants experienced discomfort following NMES. Three participants withdrew from the study due to discomfort, and one withdrew due to an unrelated oral surgery. NMES paired with high-pitch humming resulted in increased average fundamental frequency during sustained phonation and reading tasks, and increased Cepstral Spectral Index of Dysphonia during sustained phonation. Low-pitch humming resulted in a decreased noise to harmonic ratio. No statistically significant changes in perceived phonatory effort were noted. Conclusion: Almost half of the participants reported temporary discomfort. Task-specific differences in some outcomes were noted indicating that the nature of voice task performed with NMES must be considered when examining the impact of NMES on voice. Vocal tasks can impact discomfort and acoustic vocal outcomes of NMES