Cumulative Head Impact Burden in High School Football

Impacts to the head are common in collision sports such as football. Emerging research has begun to elucidate concussion tolerance levels, but sub-concussive impacts that do not result in clinical signs or symptoms of concussion are much more common, and are speculated to lead to alterations in cerebral structure and function later in life. We investigated the cumulative number of head impacts and their associated acceleration burden in 95 high school football players across four seasons of play using the Head Impact Telemetry System (HITS). The 4-year investigation resulted in 101,994 impacts collected across 190 practice sessions and 50 games. The number of impacts per 14-week season varied by playing position and starting status, with the average player sustaining 652 impacts. Linemen sustained the highest number of impacts per season (868); followed by tight ends, running backs, and linebackers (619); then quarterbacks (467); and receivers, cornerbacks, and safeties (372). Post-impact accelerations of the head also varied by playing position and starting status, with a seasonal linear acceleration burden of 16,746.1g, while the rotational acceleration and HIT severity profile burdens were 1,090,697.7-rad/sec2 and 10,021, respectively. The adolescent athletes in this study clearly sustained a large number of impacts to the head, with an impressive associated acceleration burden as a direct result of football participation. These findings raise concern about the relationship between sub-concussive head impacts incurred during football participation and late-life cerebral pathogenesis, and justify consideration of ways to best minimize impacts and mitigate cognitive declines.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/90454/1/neu-2E2011-2E1825.pd

A multi-modal virtual reality treadmill intervention for enhancing mobility and cognitive function in people with multiple sclerosis: protocol for a randomized controlled trial

BACKGROUND: Gait and cognitive impairments are common in individuals with Multiple Sclerosis (MS) and can interfere with everyday function. Those with MS have difficulties executing cognitive tasks and walking simultaneously, a reflection of dual-task interference. Therefore, dual-task training may improve functional ambulation. Additionally, using technology such as virtual reality can provide personalized rehabilitation while mimicking real-world environments. The purpose of this randomized controlled trial is to establish the benefits of a combined cognitive-motor virtual reality training on MS symptoms compared to conventional treadmill training. METHODS: This study will be a single-blinded, two arm RCT with a six-week intervention period. 144 people with MS will be randomized into a treadmill training alone group or treadmill training with virtual reality group. Both groups will receive 18 sessions of training while walking on a treadmill, with the virtual reality group receiving feedback from the virtual system. Primary outcome measures include dual-task gait speed and information processing speed, which will be measured prior to training, one-week post-training, and three months following training. DISCUSSION: This study will provide insight into the ability of a multi-modal cognitive-motor intervention to reduce dual-task cost and to enhance information processing speed in those with MS. This is one of the first studies that is powered to understand whether targeted dual-task training can improve MS symptoms and increase functional ambulation. We anticipate that those in the virtual reality group will have a significantly greater increase in dual-task gait speed and information processing speed than those achieved via treadmill training alone

Association between frailty and free-living walking performance in people with multiple sclerosis

OBJECTIVE: The purpose of this study was to examine the association between frailty and the quantity and quality of free-living walking and the mediating effect of frailty on the relationship between disability and walking performance in people with multiple sclerosis (MS). METHODS: Ninety-nine people with relapsing–remitting MS (mean age = 49.3 [SD = 9.8] y; 73.7% women; Expanded Disability Status Scale score range = 2.0–6.0) wore a triaxial accelerometer for 7 days. Recorded measures reflected the quantity (daily step counts, number of 30-second walking bouts, and signal vector magnitude) and quality (gait speed, step cadence, step and stride regularity, and sample entropy) of walking. For each walking quality measure, the typical (median), best (90th percentile), and worst (10th percentile) values were calculated. Frailty was evaluated through a 38-item frailty index. RESULTS: Participants were classified as not frail (n = 31), moderately frail (n = 34), and severely frail (n = 34) on the basis of established procedures. Patients who were moderately and severely frail exhibited poorer performance in all measures of walking quantity and quality, except for sample entropy, than individuals who were not frail. No differences in free-living walking performance were observed between the moderately and severely frail groups. Frailty did not mediate the relationship between disability (Expanded Disability Status Scale) and measures of walking quality. Conversely, frailty had a significant mediating effect on the relationship between disability and measures of walking quantity, such as daily step counts (indirect effect: b = −220.42, 95% CI = −452.03 to −19.65) and signal vector magnitude (indirect effect: b = −1.00, 95% CI = −1.86 to −0.30). CONCLUSIONS: Frailty is associated with poorer free-living walking performance in people with MS. The study findings suggest that frailty, rather than disability, may be primarily responsible for the lower amount of physical activity performed by people with MS in the real world. IMPACT: The observation that frailty and disability are differently related to measures of walking quality and quantity underscores the importance of a targeted approach to rehabilitation in people with MS

Supplementary Material for: Assessment of Postural Sway in Individuals with Multiple Sclerosis Using a Novel Wearable Inertial Sensor

Balance impairment is common in individuals with multiple sclerosis (MS). However, objective assessment of balance usually requires clinical expertise and/or the use of expensive and obtrusive measuring equipment. These barriers to the objective assessment of balance may be overcome with the development of a lightweight inertial sensor system. In this study, we examined the concurrent validity of a novel wireless, skin-mounted inertial sensor system (BioStamp®, MC10 Inc.) to measure postural sway in individuals with MS by comparing measurement agreement between this novel sensor and gold standard measurement tools (force plate and externally validated inertial sensor). A total of 39 individuals with MS and 15 healthy controls participated in the study. Participants with MS were divided into groups based on the amount of impairment (MS_Mild: EDSS 2–4, <i>n</i> = 19; MS_Severe: EDSS ≥6, <i>n</i> = 20). The balance assessment consisted of two 30-s quiet standing trials in each of three conditions: eyes open/firm surface, eyes closed/firm surface, and eyes open/foam surface. For each trial, postural sway was recorded with a force plate (Bertec) and simultaneously using two accelerometers (BioStamp and Xsens) mounted on the participant’s posterior trunk at L5. Sway metrics (sway area, sway path length, root mean square amplitude, mean velocity, JERK, and total power) were derived to compare the measurement agreement among the measurement devices. Excellent agreement (intraclass correlation coefficients >0.9) between sway metrics derived from the BioStamp and the MTx sensors were observed across all conditions and groups. Good to excellent correlations (<i>r</i> >0.7) between devices were observed in all sway metrics and conditions. Additionally, the acceleration sway metrics were nearly as effective as the force plate sway metrics in differentiating individuals with poor balance from healthy controls. Overall, the BioStamp sensor is a valid and objective measurement tool for postural sway assessment. This novel, lightweight and portable sensor may offer unique advantages in tracking patient’s postural performance

Frailty and falls in people living with multiple sclerosis

OBJECTIVE: To explore the association between frailty and history of falls in people living with multiple sclerosis (MS). DESIGN: Secondary analysis. SETTING: University research laboratories in the United States and Israel. PARTICIPANTS: 118 people with relapsing-remitting MS [age=48.9 years (SD=10.0); 74.6% female; expanded disability status scale (EDSS) range=1.0-6.0] were studied in this cross-sectional analysis. INTERVENTION: Not applicable. MAIN OUTCOMES: A frailty index was calculated from 40 health deficits by following standard validated procedures. The number of falls (12-month history) was recorded. RESULTS: Overall, 33.9%, 29.7%, and 36.4% of participants were classified as non-frail, moderately frail, and severely frail, respectively. The frailty index was significantly correlated (ρ=0.37, p<0.001) with higher scores on the EDSS. In univariable negative binomial regression analysis, the frailty index was associated with a higher number of falls (IRR=3.33, 95%CI[1.85-5.99], p<0.001). After adjustment for age, gender and EDSS, frailty remained strongly associated with history of falls (IRR=2.78, 95%CI[1.51-5.10], p=0.001). CONCLUSION: The current study identifies a significant relationship between frailty and history of falls in MS, independent of age, gender, and disease severity. These findings support the notion that frailty is a syndrome related to, but independent of, disability in MS