Importance:Repetitive head impacts (RHI) are blows to the head that do not elicit clinical signs or concussion symptoms. Yet, research suggests that brain integrity and functionality can be altered following a single season of contact collision sports. These deficits are untraceable by current clinical testing. Objective:To examine the association between RHI and oculomotor control across a single division I American football season. Design, Setting, and Participants:This single-center cohort study took place from July 2020 to May 2022. Data were analyzed from May 2022 to December 2024. Participants included 25 division I football players (11 high-dose and 14 low-dose; mean age, 20 [SD, 3] years) and 10 controls (mean age, 22 [SD, 1] years). High-dose and low-dose groups were determined by the head impacts incurred during the season using instrumented mouthguards. Exposure:A single competitive season of contact sports. Main Outcomes/Measures:All football players wore instrumented mouthguards throughout the 2 seasons (2021 to 2022). Each season was treated as an independent observation with no individual football players included in more than 1 season. A random sample of head impacts across the season were video verified. All participants completed an eye tracking task that consisted of following a Landolt-C moving horizontally during fast (90° per second) and slow (30° per second) conditions at preseason (PRE), midseason (MID), and postseason (POST). Smooth pursuit eye movement velocity was calculated and analyzed. Results:A total of 25 male division I American football student-athletes (RHI group; mean age, 20 [SD, 3] years; mean height, 185.72 [SD, 7.40] cm; mean weight, 104.02 [SD, 15.69] kg) and 10 healthy noncontact controls (7 recreationally active [4 female, 3 males] and 3 noncontact National Collegiate Athletic Association swimmers [all female]; mean age, 22 [SD, 1] years) participated in this cohort study. During the season, smooth pursuit eye movement velocity was PRE, 10.01 (SD, 3.16)° per second; MID, 11.48 (SD, 6.57)° per second; and POST, 11.10 (SD, 8.65)° per second for the high-dose group, while the low-dose group was PRE, 11.28 (SD, 4.10)° per second; MID, 11.50 (SD, 5.86)° per second; and POST, 15.02 (SD, 8.26)° per second, with the controls being PRE, 15.60 (SD, 4.44)° per second; MID, 17.95 (SD, 3.73)° per second, and POST, 13.44 (SD, 8.54)° per second. Specifically, at PRE, RHI high-dose players had slower smooth pursuit eye movement velocity compared with controls (difference, 4.28; 95% CI, 2.68-5.81; P = .01). At MID, both high-dose (difference, 8.49; 95% CI, 5.18-11.81; P = .01) and low-dose (difference, 9.15; 95% CI, 6.42-11.87; P = .02) groups had slower smooth pursuit eye movement velocities than controls. Conclusions and Relevance:In this study, smooth pursuit eye movement velocity was not affected during a single season of contact sports. Group differences suggest existing deficits before the season begins, possibly due to prior contact sport history. Interpretations should be tempered by the small sample size, single institution used for data collection, and the exploratory nature of the study.

Introduction:Walking while texting can create gait disturbances that may increase fall risk, especially in outdoors environment. To date, no study has quantified the effect of texting on motor behavior using different dynamic tasks in outdoor environments. We aimed to explore the impact of texting on dynamic tasks in indoor and outdoor environments. Methods:Twenty participants (age 38.3 ± 12.5 years, 12 F) had a Delsys inertial sensor fixed on their back and completed walk, turn, sit-to-stand, and stand-to-sit subtasks with and without texting in both indoor and outdoor environments. Results:While there was no difference in texting accuracy (p = 0.3), there was a higher dual-tasking cost in walking time with texting outdoors than indoors (p = 0.008). Discussion:Dual tasking has a greater impact on walking time outdoors compared to an indoor environment. Our findings highlight the importance of patient education concerning dual-tasking and pedestrian safety in clinical settings.

Smartphone applications are increasingly being used to measure gait due to their portability and costeffectiveness. Important reliability metrics are not available for most of these devices. The purpose of this article was to evaluate the test-retest reliability and concurrent validity of spatiotemporal gait using the novel Gait Analyzer smartphone application compared to the Tekscan Strideway. Healthy participants (n = 23) completed 12 trials of 10-meter walking, at two separate time points, using Gait Analyzer and while walking across the Tekscan Strideway. The results suggest excellent test-retest reliability for the Gait Analyzer and good test-retest reliability for the Tekscan Strideway for both velocity and cadence. At both time points, these devices were moderately to strongly correlated to one another for both velocity and cadence. These data suggest that the Gait Analyzer and Tekscan Strideway are reliable over time and can comparably calculate velocity and cadence.

BACKGROUND:Recent studies suggest that the prevalence of cardiac involvement in young competitive athletes with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection appears to be low.AIM:This study aimed to determine the prevalence of cardiovascular involvement in young competitive athletes.METHODS:In this single-center retrospective cohort study from one Division I university; we assessed the prevalence of cardiovascular involvement among collegiate athletes who tested positive for SARS-CoV-2 by polymerase chain reaction testing. Data were collected from June 25, 2020, to May 15, 2021. The primary outcome was the prevalence of cardiac involvement based on a comparison of pre- and post-infection electrocardiogram (ECGs). The secondary outcome was to evaluate for any association between ethnicity and the presence or absence of symptoms.RESULTS:Among 99 athletes who tested positive for the SARS-CoV-2 virus (mean age 19.9 years [standard deviation 1.7 years]; 31% female), baseline ECG changes suggestive of cardiovascular involvement post-infection were detected in two athletes (2/99; 2%). There was a statistically significant association between ethnicity and the presence or absence of symptoms, χ 2 (3, n = 99) = 10.61, P = 0.01.CONCLUSIONS:The prevalence of cardiovascular involvement among collegiate athletes following SARS-CoV-2 infection in this cohort is low. Afro-American and Caucasian athletes are more likely to experience symptoms following SARS-CoV-2 infection in comparison to Hispanic and Pacific Islander athletes; however, there is no association between ethnicity and symptom severity.RELEVANCE FOR PATIENTS:These data add to the growing body of the literature and agree with larger cohorts that the risk of cardiac involvement post-infection appears to be low among elite athletic and semi-professional athletic populations.

Background: It is currently unknown what specific neuronal deficits influence postural instability following SRC; however, the modulation of postural control relies heavily on the appropriate integration of sensory information from the visual, vestibular, and somatosensory system. It is possible symptom provocation of vestibular or ocular function is related to unsteady gait patterns during tandem gait. Aim: The purpose of this study was to evaluate the differences in temporal and center of pressure (CoP) metrics during discrete events of instrumented tandem gait (iTG) among those with sport-related concussion (SRC) compared to healthy controls. Secondarily, this study attempted to evaluate the relationship between iTG CoP metrics and the Vestibular/Ocular Motor Screening (VOMS) Exam. Materials and Methods: 30 collegiate athletes with SRC and 30 healthy controls completed three single task (ST) iTG trials on an instrumented walkway and the VOMS. All individuals with SRC were assessed within 24–48 h post-injury while all controls were measured during pre-participation physicals. CoP metrics in the anteroposterior (AP) and mediolateral (ML) directions and time to completion were evaluated during the first, turn and second pass of iTG between groups. VOMS score was correlated to the CoP metrics across the discrete events. Results: Athletes with SRC took longer to complete tandem gait (P<0.001) along with the first pass, second pass but not the turn when compared to the control group. SRC had slower velocity in the AP direction during both the first (P<0.001) and second pass (P<0.001) with increased postural sway in the ML direction during the first pass (P=0.014). During the turn, athletes with SRC had postural sway in the ML direction (P=0.008). Finally, VOMS score was weakly negatively related to CoP velocity in the AP direction during first (r=-0.39) and second (r=-0.36) pass while being weakly positively related to postural sway during the turn (r=-0.30). Conclusions: Athletes with SRC adopted a more conservative walking pattern and the presence of vestibular and/or ocular symptoms influence the ability to perform heel-to-toe walking. Relevance for patients: Individuals with SRC will walk slower during heel-to-toe walking and move more in the ML direction with great movement in the ML direction while en pointe turning. This may increase given the total amount of vestibular or vision symptoms following the SRC.

Tandem gait has emerged as a dynamic and clinically viable test of dynamic motor control following sport-related concussion (SRC). A myriad of tools are available to objectively assess gait kinematics. One piece of equipment, the Tekscan Strideway, uses individual load cells on a series of connected force platform tiles to quantify gait. No data exists that examines the performance of SRC using this device. PURPOSE: The purpose of this study was to evaluate the differences in center of pressure (CoP) performance during single-task (ST) and dual-task (DT) tandem gait within 24-48 hours postSRC. METHODS: 18 Division I [SRC (age: 19 ± 1.00 yr. Male=7, Female=11)] and 18 nearly matched controls [CON (age: 19.88 ± 1.05 yr. Male=7, Female=11)] completed the vestibular ocular motor screening test (VOMS) and 3 trials of ST and 1 trial of DT (serial 7s) using the Tekscan Strideway (30Hz, Boston, MA). The raw CoP trajectory for the best tandem gait trial of each condition (fastest overall) was exported and further analyzed using a custom MATLAB code. All turns during the tandem gait trials were removed and each straight path walking was composed together. The raw CoP data in the AP and ML directions were smoothed using empirical mode decomposition and then excursion and velocity data were calculated. T-tests compared the time to complete ST and DT while two multivariate ANOVAs compared CoP in the AP and ML directions. RESULTS: SRC took significantly longer to complete the ST trial (p=.006; SRC=14.2±4.4s, CON=10.8±2.1s) but not the DT trial (p=.279). The SRC group had a larger VOMS near-point convergence (NPC) (p=.007; SRC=9.5±5.5cm, CON=5.2±2.9cm) and a higher VOMS change score (p<.001; SRC=19.7±6.4, CON=0±0). A significant omnibus effect was noted in AP direction (p=.015) but not in the ML direction (p=.996) for the tandem gait CoP data. Follow-up comparisons noted that in the AP direction during ST, SRC had slower CoP excursion (p=.003; SRC=1.6±0.2cm, CON=1.9±0.4cm) and lower CoP velocity (p=.004; SRC=54.2±7.7cm/s, CON=66.1±14.2cm/s) but no differences during DT. CONCLUSIONS: These results suggest that during instrumented ST tandem gait, SRC have a more conservative and slower heel-to-toe stepping pattern.

CONTEXT:Lower extremity musculoskeletal (LEMSK) injury may be more prevalent among those with a history of sport-related concussion (SRC).OBJECTIVE:To investigate the relationship between baseline postural control metrics and the LEMSK injury incidence in National Collegiate Athletic Association Division I student-athletes with a history of SRC.SETTING:National Collegiate Athletic Association Division I athletes.DESIGN:Cohort study.PATIENTS OR OTHER PARTICIPANTS:Of 84 total athletes (62 males), 42 had been previously diagnosed with an SRC, and 42 were matched controls based on age, sex, height, weight, and sport.MAIN OUTCOME MEASURE(S):During the preseason baseline evaluation, all participants performed 3 trials of eyes-open and eyes-closed upright quiet stance on a force platform. Medical charts were assessed for all the LEMSK injuries that occurred from preseason baseline to 1 year later. Center-of-pressure data in the anteroposterior and mediolateral directions were filtered before we calculated root mean square and mean excursion velocity; the complexity index was calculated from the unfiltered data. Factorial analysis-of-variance models were used to examine differences between groups and across conditions for root mean square; mean excursion velocity, complexity index, and tests of association to examine between-groups LEMSK differences; and logistic regression models to predict LEMSK.RESULTS:Concussion history and injury incidence were related in the SRC group (P = .043). The complexity index of the SRC group was lower with eyes closed (14.08 ± 0.63 versus 15.93 ± 0.52) and eyes open (10.25 ± 0.52 vs 11.80 ± 0.57) in the mediolateral direction than for the control participants (P < .05). Eyes-open root mean square in the mediolateral direction was greater for the SRC group (5.00 ± 0.28 mm) than the control group (4.10 ± 0.22 mm). Logistic regression models significantly predicted LEMSK only in control participants.CONCLUSIONS:These findings may suggest that LEMSK after SRC cannot be predicted from postural-control metrics at baseline.

*School of Community Health Sciences, †Neuroscience Institute, and ‡School of Medicine, University of Nevada, Reno; §Waters School of Health Professions, Georgia Southern University, Statesboro; ||Doctor of Physical Therapy Program, West Coast University Center for Graduate Studies, Los Angeles, CA; ¶UGA Concussion Research Laboratory, University of Georgia, Athens; #Department of Kinesiology and Applied Physiology and Biomechanics and Movement Science Interdisciplinary Program, University of Delaware, Newark; **Exercise Neuroscience Research Laboratory, School of Health Studies, University of Memphis, TN

PURPOSE: The purpose of this study was to examine the relationship between ApEn, SampEn, and CI in a group of healthy match controls (CON) and sport-related concussion (SRC). METHODS: Sixteen Division 1 athletes with SRC and 16 CON performed 3 trials of feet together quiet upright stance in the eyes open (EO) and eyes closed (EC) conditions for 30 seconds on a force platform (100Hz) at 24-48 hours post-injury. SRC was diagnosed by the head team physician and verified by the presence of 2 or more vestibular/ocular symptom scores on Vestibular Ocular Motor Screening (VOMS) test. CON data were collected at pre-participation physicals. Raw CoP data were analyzed using ApEn and SampEn (m=2, r=0.2, N=300), and MSE (m=2, r=0.15, S=1-10, N=300-3,000). The data were analyzed using independent samples t-tests and Pearson’s Product Correlations. RESULTS: A significant decrease in ApEn (p=0.024; SRC=0.59±0.11, CON=0.68±0.10 Cohen’s d= 0.86) SampEn (p=0.022; SRC=0.65±0.14, CON=0.76±0.13, Cohen’s d= 0.81), and MSE (p=0.025; SRC=41.86±8.79, CON=48.69±7.55, Cohen’s d= 0.83) was noted in the EC AP direction for SRC. No other significant differences were noted. A significant relationship was noted between ApEn and SampEn (p<0.001, r=0.99), ApEn and MSE (p<0.001, r=0.99), and SampEn and MSE (p<0.001, r=0.99) in the EC AP direction for both SRC and CON. CONCLUSION: These results may indicate that ApEn, SampEn, and MSE are highly related to one another and may be viable in determining deficits postural control following SRC.

Falls are a common cause of traumatic brain injuries (TBI) across the lifespan. A proposed but untested hypothesis is that neck muscle activation influences impact severity and risk for TBI during a fall. We conducted backward falling experiments to test whether activation of the neck flexor muscles facilitates the avoidance of head impact, and reduces impact velocity if the head contacts the ground. Young adults (n=8) fell from standing onto a 30cm thick gymnastics mat while wearing a helmet. Participants were instructed to fall backward and (a) prevent their head from impacting the mat ("no head impact" trials); (b) allow their head to impact the mat, but with minimal impact severity ("soft impact" trials); and (c) allow their head to impact the mat, while inhibiting efforts to reduce impact severity ("hard impact" trials). Trial type associated with peak magnitude of electromyographic activity of the sternocleidomastoid (SCM) muscles (p<0.017), and with the vertical and horizontal velocity of the head at impact (p<0.001). Peak SCM activations, expressed as percent maximal voluntary isometric contraction (%MVIC), averaged 75.3, 67.5, and 44.5%MVIC in "no head impact", "soft impact", and "hard impact" trials, respectively. When compared to "soft impact" trials, vertical impact velocities in "hard impact" trials averaged 87% greater (3.23 versus 1.73m/s) and horizontal velocities averaged 83% greater (2.74 versus 1.50m/s). For every 10% increase in SCM %MVIC, vertical impact velocity decreased 0.24m/s and horizontal velocity decreased 0.22m/s. We conclude that SCM activation contributes to the prevention and modulation of head impact severity during backward falls.

OBJECTIVE:The purpose of this study was to evaluate the influence of a posture-cuing shirt on internal rotation velocity of the shoulder during a tennis swing and to determine this influence on shoulder external rotation position. METHODS:Nine healthy competitive college tennis players from a Division III college participated in this study. High-speed motion capture allowed for 3-dimensional analysis of shoulder kinematics during a tennis serve. Two conditions were evaluated while the athletes performed a high-velocity tennis serve: a standard tennis shirt and a posture-cuing shirt. RESULTS:Shoulder internal rotation velocity increased when wearing the posture-cuing shirt. Peak internal rotation velocity increased from 960.61°/s ± 93.24°/s to 1217.96°/s ± 155.01°/s (t = -1.76, P = .058). Internal rotation velocity at the time of impact increased from 765.18°/s ± 95.48°/s to 900.54°/s ± 105.33°/s (t = -1.50, P = .086). Shoulder maximum external rotation did not differ between the 2 conditions, at 172.00° ± 2.92° and 170.89° ± 3.70° (t = 0.325, P = .754). CONCLUSIONS:Wearing a posture-cuing shirt may possibly alter shoulder kinematics during an overhead sport activity such as tennis. Internal rotation velocity seemed to improve while wearing this shirt, although shoulder external rotation position did not change. It is not known if these improvements can influence injury risk.

Summary Study aim: this study examined the item difficulty and item discrimination scores for the HRFK PE Metrics cognitive assessment tool for 5th-grade students. Materials and methods: ten elementary physical education teachers volunteered to participate. Based on convenience, participating teachers selected two 5th grade physical education classes. Teachers then gave students (N = 633) a 28-question paper and pencil HRFK exam using PE Metrics Standards 3 and 4. Item difficulty and discrimination analysis and Rasch Modeling were used data to determine underperforming items. Results: analysis suggests that at least three items are problematic. The Rasch Model confirmed this result and identified similar items with high outfit mean square values and low Point Biserial correlation values. Conclusions: teachers are in need of valid and reliable HRFK assessment tools. Without the removal of three items in the PE Metrics HRFK exam for 5th-grade students, complete use of the exam could offer incorrect conclusions.

The association between self-reported smoking and overuse injury in a cohort of young men (n = 900) and women (n = 597) undergoing 12 weeks of standardized military instruction, after adjustment for physical activity, health history, and incoming fitness tests was examined. The outcome includes all International Classification of Diseases, 9th Revision codes related to injuries resulting from cumulative microtrauma (overuse injuries). The short survey asked about the subject's demographics, smoking habits, prior injuries sustained, physical activity level, self-perceived fitness, and (for women) menstrual history. From the survey, 4 questions established smoking behavior: smoked at least 100 cigarettes in lifetime, age smoked a whole cigarette for the first time, how many cigarettes smoked during the last 30 days, and how many cigarettes smoked per day during the last 30 days. None of the adjusted hazard ratios for the smoking questions were associated with an increased risk of overuse injury for either sex. Furthermore, this study did not find a significant association with respect to smoking and all injuries in either men or women. In conclusion, smoking does not appear to be an independent risk factor for overuse injury in either young men or women during 12 weeks of standardized military instruction.

OBJECTIVE:The purpose of this study was to evaluate the opinions of experienced cyclists on perceived influence of a posture-cueing shirt with compressive properties on their comfort and recovery. METHODS:Twenty experienced cyclists wore a compressive shirt during rides and as a postride recovery shirt; cyclists rated their perceived experiences during rides and recovery. They completed 2 separate questionnaires specific to riding or recovery; scores ranged from - 3.0 (negative influence) to + 3.0 (positive influence), addressing posture, discomfort, breathing, and recovery. Data analysis included frequencies and t tests to compare groups. RESULTS:Cyclists completed 53 rides, averaging 95.48 km (SD = 31.72 km), wearing the shirt and reported a perceived benefit (mean score = 1.17, SD = 0.25). For their postride recovery perceptions, scores averaged 1.99 (SD = 0.48) for perceived benefits for recovery. No differences in scores were identified between male and female cyclists during rides (t = - 0.28, P > .05); however, female riders perceived greater benefit during recovery (t = - 2.24, P < .05). There were no correlations with scores and cyclist age, experience, or ride distances during rides or recovery (r = 0.02-0.35). CONCLUSION:A posture-cueing, compressive shirt was rated to have a perceived benefit by experienced cyclists for riding posture, postride posture, spine discomfort, and postride recovery. This study did not evaluate physical or physiologic variables to confirm these perceptions.

Weightlifters have commonly believed that changing joint position can alter specific muscle activation. The magnitude of force produced by a muscle is highly dependent upon the length of the muscle. The purpose of this study was to determine the effect of foot positioning on muscle activation of the superficial quadriceps as measured by surface electromyography (sEMG) during a functional squatting movement in healthy adults. Twenty physically active asymptomatic adults (7 females and 13 males) were included in the study while four different foot positions (Neutral, Internally Rotated, Externally Rotated, and Staggered) were assessed. Three quadriceps muscles (Rectus Femoris (RF), Vastus Medialis Oblique (VMO), and Vastus Lateralis Oblique(VLO) were measured. Raw EMG was transformed using a root mean square algorithm. Six one-way repeated measure ANOVAs were conducted to examine the peak and average RMS amplitude for each muscle across each condition, with an alpha level of 0.05 set a priori. Across all foot positions only the Staggered foot position reached statistical significance when compared to all other foot positions for each muscle group. Results suggest that altering the foot position during a partial weight squat has little to no effect on the EMG amplitudes of the quadriceps. However, more research is needed to examine the concentric and eccentric phases of the squatting motion separately with the addition of full weight bearing squats.

This prospective study evaluated the association of self-reported health habits and behaviors in 2,930 Navy recruits with poor training outcomes, defined as graduating late or separating from training. Although 17% of the men and 21% of the women had a poor training outcome, results suggest that some self-reported measures were associated with poor training outcomes. Men who did not run or jog at least 1 month before basic training or had a previous lower limb injury without complete recovery and women reporting the same or less physical activity compared with their same-age counterparts were more likely to have a poor training outcome. An important first step in decreasing poor training outcomes is encouraging incoming recruits to participate in physical activity and taking steps to identify and rehabilitate recruits who are not completely healed from a lower limb musculoskeletal injury before reporting to basic training.

Straub, RK and Cipriani, DJ. Influence of infrapatellar and suprapatellar straps on quadriceps muscle activity and onset timing during the body-weight squat. J Strength Cond Res 26(7): 1827-1837, 2012-The use of knee braces for the treatment of patellofemoral pain syndrome (PFPS) is widely documented, yet the mechanism by which such braces alleviate knee pain remains unclear. This study attempted to clarify this issue by simplifying the brace to the level of only straps. The effectiveness of an infrapatellar strap for PFPS remains controversial, and the use of a suprapatellar strap has not yet been studied. Quadriceps muscle activity and onset timing parameters were measured with surface electromyography (EMG) during a body-weight squat in 19 healthy subjects during 4 different knee-strapping conditions (infra, supra, both, and none). No differences in normalized mean or peak EMG activity in any part of the quadriceps were found. The onset timing of the vastus lateralis (VL) was significantly delayed when using an infrapatellar strap (p < 0.05) or both straps (p < 0.05) and marginally delayed when using a suprapatellar strap (p < 0.10) in comparison with the no-strap (control) condition. No differences in the vastus medialis oblique (VMO) onset timing or VMO-VL onset timing difference were found among the strapping conditions, although an improvement in timing was noted with the suprapatellar condition. The results provide novel evidence that the application of an infrapatellar strap, suprapatellar strap, or both straps improves quadriceps muscle timing imbalances by delaying VL onset. Because the largest delay in VL onset occurred when wearing both straps, the combined application of an infrapatellar and suprapatellar strap may be the most beneficial in managing patellofemoral pain. Knee straps, unlike braces, are cost effective, nonrestrictive, and can be universally fitted to any knee and based on the results deserve further study in the patellofemoral pain population.

CONTEXT:The Bodyblade Pro is used for shoulder rehabilitation after injury. Resistance is provided by blade Oscillations-faster oscillations or higher speeds correspond to greater resistance. However, research supporting the Bodyblade Pro's use is scarce, particularly in comparison with dumbbell training. OBJECTIVE:To compare muscle activity, using electromyography (EMG), in the back and shoulder regions during shoulder exercises with the Bodyblade Pro vs dumbbells. DESIGN:Randomized crossover study. SETTING:San Diego State University biomechanics laboratory. PARTICIPANTS:11 healthy male subjects age 19-32 y. INTERVENTION:Subjects performed shoulder-flexion and -abduction exercises using a Bodyblade Pro and dumbbells (5, 8, and 10 lb) while EMG recorded activity of the deltoid, pectoralis major, infraspinatus, serratus anterior, and erector spinae. MAIN OUTCOME MEASURES:Average peak muscle activity (% maximum voluntary isometric contraction) was separately measured for shoulder abduction and flexion in the range of 85° to 95°. Differences among exercise devices were separately analyzed for the flexed and abducted positions using 1-way repeated-measures ANOVA. RESULTS:The Bodyblade Pro produced greater muscle activity than all the dumbbell trials. Differences were significant for all muscles measured (all P < .01) except for the erector spinae during shoulder flexion with a 10-lb dumbbell. EMG activity for the Bodyblade Pro exceeded 50% of the MVIC during both shoulder flexion and abduction. For the dumbbell conditions, only the 10-lb trials approached this effect. CONCLUSIONS:Using a Bodyblade during shoulder exercises results in greater shoulder- and back-muscle recruitment than dumbbells. The Bodyblade Pro can activate multiple muscles in a single exercise and thereby minimize the need for multiple dumbbell exercises. The Bodyblade Pro is an effective device for shoulder- and back-muscle activation that warrants further use by clinicians interested in its use for rehabilitation.