Context: Running is a popular form of physical activity but can increase an individual’s lower-extremity injury risk. Running gait analysis via inertial measurement units (IMUs) is a method for collecting important gait data that is related to developing lower-extremity injuries, such as increased load from low step rate (SR), and long stride length (SL). IMU data can be derived from both foot- and shank-placed IMUs, but foot-placed sensors (RunScribe IMUs) need validation against shank-placed sensors. Purpose: Determine criterion validity of RunScribe foot-placed IMUs against MyoMotion shank-placed IMU for SR and SL. Design: cross-sectional laboratory study. Methods: Nine participants (5 males, 4 females; age: 28.33 [5.78]; height: 1.75 [0.11]; mass: 74.06 [16.24]) volunteered for our study. Following a 5-minute warm-up, participants ran on a treadmill for 5 minutes at a self-selected speed. After ∼2.5 minutes, MyoMotion data were collected for 10 seconds. The RunScribe IMUs collected data throughout the full duration of the run. Criterion validity of SR and SL between the foot- and shank-placed IMUs was determined using bivariate Pearson correlations, intraclass correlation coefficients (3,1), and Bland–Altman plots with 95% limits of agreement analysis. Results: A very strong correlation for SR (r = .90, N = 9, P ≤ .001), and a strong correlation for SL (r = .80, N = 9, P < .001) were found between the foot and shank-placed IMUs. Excellent reliability was found for SR (intraclass correlation coefficient = .91, P ≤ .001, 95% CI, .639–.978), and good reliability was found for SL (intraclass correlation coefficient = .800, P = .003, 95% CI, .340–.951) between the foot and shank-placed IMUs. The mean difference of SR and SL was −2.111 and −0.142, respectively, indicating good agreement between the foot and shank-placed IMUs. Conclusions: Foot-placed RunScribe IMUs are a valid alternative for measuring SR and SL compared with shank-placed IMUs.
Browse
Foot-Placed Inertial Measurement Units Are Valid Against Shank-Placed Units When Measuring Temporospatial Running Variables
Madison S. Mach, Hayley Ericksen, Erin Lally, and Jennifer E. Earl-Boehm
Countermovement Jump Performance Is Altered by Visual and Auditory Cognitive Dual Tasking in Recreationally Active Young Adults: A Cross-Sectional Study
Jacob M. Thomas, Jamie B. Hall, and Trent M. Guess
In sports settings, it is important to understand and assess the effects of cognitive–motor interference on sport-specific tasks throughout strength and conditioning programs to better represent the athletic environment. This study used a low-cost movement assessment system, the Mizzou Point-of-care Assessment System, to measure the effects of visual and auditory cognitive–motor dual tasking on countermovement jump (CMJ) performance. Thirty-one recreationally active adults (21.1 [1.9] y, 168.9 [11.8] cm, 69.1 [13.6] kg) participated. Participants performed 3 trials of CMJ under 3 conditions: control, audio dual tasking, and visual dual tasking. Tasks were assessed using a low-cost system comprising a custom force plate, depth camera, and interface board. Repeated-measures analysis of variance with post hoc t tests revealed significant decreases in several kinematic and kinetic outcome measures, including time in the concentric phase (in seconds; 95% CI mean difference audio–control = −0.045 to 0.0054; visual–control = −0.045 to 0.0054), time to takeoff (in seconds; audio–control = −0.026 to 0.086; visual–control = −0.026 to 0.086), jump height (in meters; audio–control = −0.0081 to 0.048; visual–control = −0.01 to 0.05), maximum knee flexion (in degrees) at jump (audio–control = 1.47 to 9.89; visual–control = −1.58 to 9.66), hip flexion (in degrees) at maximum knee flexion during jump (audio–control = 0.00 [0.00 to 0.00]; visual–control = 0.00 [0.00 to 0.00]), and several others for both dual tasking conditions compared with control but not between audio and visual conditions. Results indicate that both dual task conditions negatively impact CMJ performance and that their effects can be effectively quantified using a low-cost assessment tool.
Physical Fitness, Interlimb Asymmetry, and Injury Reports in Judo Athletes With Vision Impairments: A Cross-Sectional Study
Raiane Carvalho, Marina Saldanha da Silva Athayde, Jaime Roberto Bragança, Daniele Detanico, and Rafael Lima Kons
Context: Investigating parameters related to physical capacities, muscular imbalance between the limbs, and injury reports in judo athletes with vision impairments (VI) is something extremely relevant for competitive performance, especially considering the absence of vision, which can be a determining factor in these aspects. For this, this study aimed to explore the interlimb asymmetry and bilateral strength index in upper and lower limbs in judo athletes with VI and describe the injury reports and the association with the muscular imbalance. Design: A cross-sectional study. Methods: Eighteen judo athletes with VI participated in this cross-sectional study. Athletes performed the following physical tests: handgrip strength, countermovement jump, and medicine ball throw. All tests were performed unilaterally and bilaterally to calculate the interlimb asymmetry and the bilateral strength index. After this, an injury questionnaire was applied, considering injuries that occurred in the previous 6 months. Student t tests and chi-square tests were used to compare groups and test the associations between injury reports, adopting the level of 5%. Results: The results demonstrated that performance was higher for male compared with female athletes (P < .05) and asymmetry was influenced by sex (higher for male; P < .05) and the origin of the impairment (higher for acquired; P < .05). Furthermore, the bilateral strength deficit was more present in injured groups (mainly in medicine ball throw and countermovement jump). Finally, the most common mechanism of injury was direct contact with another athlete. Conclusion: Muscle imbalances were identified in male and female VI judo athletes and seem to be related to injury reports.
Volume 34 (2025): Issue 3 (Mar 2025): Concussion Rehabilitation: Methods, Determinants, and Outcomes
Successful Rehabilitation Following Stem Cell Therapy for Large Knee Osteochondritis Dissecans in an Adolescent Wrestler
Han Soo Park and Jae Keun Oh
Context: Detailed rehabilitation protocols after stem cell treatment are lacking. This case highlights the rehabilitation of a patient treated with human umbilical cord blood-derived mesenchymal stem cell implantation for a large osteochondritis dissecans lesion of the knee. Case presentation: A 17-year-old male adolescent wrestler experienced persistent left knee pain for 1 year, unresponsive to 6 months of conservative treatment. MRI revealed a large osteochondritis dissecans lesion (38 × 18 mm) in the lateral femoral condyle, which was treated with human umbilical cord blood-derived mesenchymal stem cell implantation. Management and outcomes: Rehabilitation was conducted in 4 phases. The protection phase (1–8 wk) emphasized weight-bearing restrictions, continuous passive motion, and early gait training. The gait recovery phase (9–12 wk) incorporated stationary cycling and open kinetic chain exercises. During the maturation phase (13–24 wk), maximal strength and proprioception exercises were introduced with antigravity treadmill running. The final recovery phase (24–52 wk) focused on plyometric drills and sport-specific activities. Team training resumed at 32 weeks, and return to full competitive training occurred at 52 weeks. The limb symmetry index for isokinetic knee-extensor strength and single-leg hop test reached 95.2% and 97.9%, respectively, by 12 months, indicating near-complete functional recovery. The modified MRI of cartilage repair tissue score improved from 40 to 60 points between 1 and 3 years postsurgery. Second-look arthroscopy revealed an International Cartilage Repair Society grade 1 at 35 months. International Knee Documentation Committee scores increased from 17.2 preoperatively to 98.9 at 2 years, while visual analog scale scores decreased from 10 to 2 over 3 years. Conclusions: Accelerated weight bearing, early gait training, and phased strength exercises facilitated substantial improvements in function and cartilage healing in an adolescent wrestler with a large osteochondritis dissecans lesion. Further studies with larger cohorts are recommended to confirm these findings.
Exploring New Frontiers in Concussion Rehabilitation
Johna K. Register-Mihalik and David R. Howell
The Effects of Different Core Stability Training on Trunk Stability and Athletic Performance in Adolescent Female Basketball Players
Ian-Ju Liang, Linda L. Lin, and Chen-Chia Huang
Purpose: Trunk function is not only related to physical fitness performance, but also important for the balance, and stability of the whole body. This study aimed to investigate the effects of 2 training methods on trunk stability and athletic performance in adolescent female basketball players. Methods: Fifty-one healthy elite female basketball players (age: 14.76 [1.84] y, body mass index: 21.41 [1.96] kg/m2) were assigned to TRX training (n = 17), Swiss ball training (n = 17), or control groups (n = 17). Participants performed a progressive program of unstable core muscle training consisting of 8 different exercises, with each exercise performed in 3 sets, twice a week for 8 weeks. The outcome measures were a plank test, the modified double leg lowering task, and athletic performance including jumping, speed, agility, cardiopulmonary endurance, and the ankle proprioception. Results: Significant group and time interaction were identified in the modified double leg lowering task (P = .032, η 2 = .134), with post hoc comparisons revealing improvements in the TRX group (P = .014). The TRX group (8.6%) improved significantly more than the Swiss ball group (2.9%) when it comes to the modified double leg lowering average change percentage. The plank test also exhibited a significant group and time interaction (P = .033, partial η 2 = .133), with notable improvements in both the Swiss ball (P = .001) and the TRX groups (P = .001). Athletic performance measures showed no significant differences among groups. Conclusions: The results indicate that both TRX and Swiss ball training can increase core muscle strength and stability without compromising athletic performance after 8 weeks of training. Furthermore, incorporating core muscle training enhances power transmission capabilities. Nevertheless, considering the goal was to improve speed and ankle proprioception during preseason training, careful consideration must be given to the timing and intensity of any intervention involving unstable core muscle training.
Normative Hip Range of Motion and Strength Profiles of Uninjured Baseball Athletes: A Systematic Review
Sean M. Kennedy, Joseph P. Hannon, Reagan M. Morrow, J. Kaylin Kruseman, Frankie-Ann McCauley, Jacob E. Vasquez, James L. Farnsworth, Amanda J. Arnold, and Natalie L. Myers
Context: The baseball athlete incorporates the use of the entire kinetic chain while throwing. Hip range of motion (ROM) and strength have been previously studied in its relation to injury development. It is a clinical necessity to understand the normative profiles of hip musculoskeletal function across the playing career. Objectives: To identify the normative hip ROM and strength profiles of baseball players across level of play. Evidence Acquisition: The researchers searched the electronic databases MEDLINE, SPORTDiscus, CINAHL, and Embase using a custom search strategy. After applying inclusion and exclusion criteria, 31 articles were reviewed. Of these 31 articles, 22 examined hip ROM and/or strength in uninjured baseball athletes. A manual search of the references of those 22 articles revealed 4 additional articles that met the inclusion criteria. In total, 26 articles were included in data collection. Evidence Synthesis: Articles were assessed for quality using the appraisal tool for cross-sectional studies. The appropriate hip ROM and strength data, along with player demographics, were extracted and reviewed to ensure accuracy. Articles were also categorized based on level of play and player position. Conclusions: Hip ROM and strength profiles of baseball athletes across all levels of play were identified and presented to comprehensively summarize the available data on normative musculoskeletal hip profiles. Observed differences between positions and across levels of play were documented. In general, hip external rotation ROM was greater than internal rotation across all levels and between the stance and lead limbs. As age and level of play increased, the difference between hip external rotation and internal rotation ROM also increased. Hip strength increased as level of play (and subsequently age) increased. These summarized data can be used as benchmarks to compare clinical populations.
Influence of Step Rate Manipulation on Foot Strike Pattern and Running Economy
Youngwook Kim, Janae L. Richardson, and Eadric Bressel
Context: With the rise in distance running, there is an increasing interest in reducing running-related injuries and improving performance. Foot strike patterns (FSP) and step rate (SR) are key factors in managing the external forces generated during foot contact in running. Adjusting SR may help alter FSP and improve running economy (RE), yet its effects on recreational runners are not fully understood. Thus, this study aimed to examine if SR manipulations are sufficient to shift FSP and whether the manipulations change the RE. Design: Cross-sectional study. Methods: Eighteen healthy recreational runners’ (age: 30.2 [7.6] y) foot strike angle was calculated using 2D video motion analysis, and submaximal VO2 was measured while running on a treadmill during preferred and adjusted (±5% and ±10%) SR conditions. Foot strike angle was used to predict strike index and quantify FSP, and submaximal VO2 was analyzed to determine RE. Results: Predicted strike index was significantly different between preferred SR and the −10% (P = .002), −5% (P = .002), and +10% (P < .001) SR conditions. Submaximal VO2 was significantly increased in the −10% (P < .001) and −5% (P = .002) SR conditions. Conclusion: SR manipulations were sufficient to alter foot strike angle and predicted strike index in recreational runners, leading to moderate to significant changes in RE. These findings suggest that SR manipulation can be a useful tool for influencing FSPs and optimizing RE to enhance performance and reduce injury risk.
Kinesiophobia in Collegiate Athletes and Nonathletes With and Without Chronic Ankle Instability
Nadia M. Perez, L. Kent Griffin, Randall E. Osborne, and Rachel M. Koldenhoven
Context: Kinesiophobia is a substantial psychological factor that may impact sport performance and activities of daily living for individuals with chronic ankle instability (CAI). The purpose of this study was to determine the levels of kinesiophobia between collegiate athletes and nonathletes with and without CAI using quantitative and qualitative analyses. Design: Cross-sectional survey. Methods: A Qualtrics survey was distributed to college students. Ankle health status was evaluated using the Foot and Ankle Ability Measure Sport subscale, Identification of Functional Ankle Instability, and history questions. Kinesiophobia was assessed using the Tampa Scale of Kinesiophobia-11. A 4 × 2 analysis of variance was used to assess differences in athlete status (NCAA Division 1, intramural, club, and nonathlete) and ankle health status (CAI and healthy). An open-ended question was added to understand how kinesiophobia impacts individuals CAI. Data were analyzed via content analysis. Results: Of the 531 respondents who completed the survey, 140 (116 = CAI and 24 = healthy) met the inclusion criteria for the study. There was a significant main effect for ankle health status for the Foot and Ankle Ability Measure Sport (CAI = 62.68 [15.11]%, healthy = 99.57 [0.01]%), Identification of Functional Ankle Instability (CAI = 21.63 [5.34], healthy = 2.42 [2.93]), and Tampa Scale of Kinesiophobia-11 (CAI = 26.04 [6.22], healthy = 16.75 [5.50]). There were no significant main effects for athlete status or interactions for any variables. Perceptual and behavioral responses were to major categories identified with the qualitative analysis. Fear, pain, and instability were higher order themes within perceptual responses. Activity avoidance and bracing were higher order themes within behavioral responses. Conclusion: This study highlights the significant role of kinesiophobia in individuals with CAI, with those affected reporting higher levels of fear, pain, and instability compared with healthy individuals. Behavioral adaptations such as activity avoidance and bracing were common among qualitative responses. While no differences were observed across athlete statuses, these findings underscore the need for tailored interventions addressing both physical and psychological factors to improve outcomes for individuals with CAI.