It is known that high-performance sprinters with unilateral and bilateral prosthetic lower limbs run at different speeds using different spatiotemporal strategies. Historically, these athletes still competed together in the same races, but 2018 classification rule revisions saw the separation of these two groups. This study sought to compare Paralympic sprint performance between all-comer (i.e., transfemoral and transtibial) unilateral and bilateral amputee sprinters using a large athlete sample. A retrospective analysis of race speed among Paralympic sprinters between 1996 and 2016 was conducted. In total, 584 published race results from 161 sprinters revealed that unilateral and bilateral lower-extremity amputee sprinters had significantly different race speeds in all three race finals (100 m, p value <.001; 200 m, <.001; 400 m, <.001). All-comer bilateral amputee runners ran faster than their unilateral counterparts; performance differences increased with race distance. These data support current classification criteria in amputee sprinting, which may create more equal competitive fields in the future.
Yetsa A. Tuakli-Wosornu, Xiang Li, Kimberly E. Ona Ayala, Yinfei Wu, Michael Amick, and David B. Frumberg
Although the dynamics of center of mass can be accounted for by a spring-mass model during hopping, less is known about how each leg joint (ie, hip, knee, and ankle) contributes to center of mass dynamics. This work investigated the function of individual leg joints when hopping unilaterally and vertically at 4 frequencies (ie, 1.6, 2.0, 2.4, and 2.8 Hz). The hypotheses are (1) all leg joints maintain the function as torsional springs and increase their stiffness when hopping faster and (2) leg joints are controlled to maintain the mechanical load in the joints or vertical peak accelerations at different body locations when hopping at different frequencies. Results showed that all leg joints behaved as torsional springs during low-frequency hopping (ie, 1.6 Hz). As hopping frequency increased, leg joints changed their functions differently; that is, the hip and knee shifted to strut, and the ankle remained as spring. When hopping fast, the body’s total mechanical energy decreased, and the ankle increased the amount of energy storage and return from 50% to 62%. Leg joints did not maintain a constant load at the joints or vertical peak accelerations at different body locations when hopping at different frequencies.
Nathálya Gardênia de Holanda Marinho Nogueira, Bárbara de Paula Ferreira, Fernanda Veruska Narciso, Juliana Otoni Parma, Sara Edith Souza de Assis Leão, Guilherme Menezes Lage, and Lidiane Aparecida Fernandes
This study investigated the influence of chronotype on motor behavior in a manual dexterity task performed at different times of the day. Sixteen healthy adults of each chronotype (morning, evening, and neither), as measured by the Morningness–Eveningness Questionnaire, practiced both conditions of the Grooved Pegboard Test either in the morning or in the afternoon to early evening. The “neither” chronotype (65.12 ± 7.46) was outperformed (ps ≤ .03) by both the morning (56.09 ± 7.21) and evening (58.94 ± 7.53) chronotypes when the task had higher cognitive and motor demand but was not outperformed in the task with lower demand (morning = 18.46 ± 2.11; evening = 19.34 ± 2.79; neither = 21.47 ± 2.54; p > .05). No difference between the morning and evening chronotypes was found at the different times of the day (ps > .05), suggesting that a manual dexterity task is not sufficiently demanding to be influenced by chronotype.
Victoria Sanborn, Lauren Todd, Hanna Schmetzer, Nasha Manitkul-Davis, John Updegraff, and John Gunstad
Anxiety and depressive symptoms are prevalent in athletes. The pandemic of novel coronavirus (COVID-19) may increase risk for symptoms due to fear of exposure during competition or uncertainty regarding participation. The current study examined the prevalence of COVID-19 anxiety in 437 National Collegiate Athletic Association Division I student-athletes and its association with psychological symptoms. Only 0.2% of participants endorsed COVID-19 anxiety symptoms above cutoff. COVID-19 anxiety did not change after postponement of fall sports or differ between persons competing in different seasons. However, higher levels of COVID-19 anxiety were significantly associated with depression, anxiety, and stress. Though student-athletes generally reported low levels of psychological symptoms, females endorsed significantly higher levels than males. Low levels of COVID-19 anxiety in student-athletes may reflect protective factors (e.g., health knowledge, emotion regulation) or the tendency for this population to minimize psychological symptoms. Further investigations on the psychological impact of COVID-19 in athletes is needed.
Félix Croteau, Shawn M. Robbins, and David Pearsall
Context: Previous authors suggest that lack of strength is an important risk factor for injuries in water polo. Hand-held dynamometers have potential as a clinical tool to measure strength, but they have not been validated in water polo players. Objective: The purpose of this study was to estimate intertrial variability and concurrent validity of hand-held dynamometer shoulder strength measurements in elite water polo players. Methods: A total of 19 male and 20 female elite water polo players performed isometric external (ER) and internal (IR) rotation strength tests against a hand-held dynamometer bilaterally in supine position with the shoulder in a 90–90 position. In addition, concentric IR and ER was captured at 90 deg/s with an isokinetic dynamometer, and torque values were determined near the 90–90 position. Main Outcome Measures: Spearman correlation coefficients were calculated for ER torque, IR torque, and ER/IR ratios between the devices. Two-way mixed-model intraclass correlations were used to assess intertrial variability. Results: Correlations between the devices were strong to very strong (ρ = .65–.82, P < .01) for absolute IR and ER but low for ER/IR ratios (ρ = .29, P = .07). There was less agreement at higher torque values. Intertrial variability was low with intraclass correlation values .88 to .93, P < .05. Conclusions: These results show that hand-held dynamometers are adequate clinical alternatives to measure absolute shoulder strength in water polo players. Stronger players may require stronger evaluators to resist the player’s push and obtain reliable results.
Tyler A. Wood, Jake M. Tablerion, Randy A. Ballard, Jerrad Zimmerman, and Jacob J. Sosnoff
There is minimal biomechanical research examining head impacts in noncollision sport, such as diving. This pilot study quantified the number of head impacts and magnitude of linear head acceleration in collegiate divers. Three participants wore instrumented swim caps for 10 practice sessions. A total of 1,271 dives were recorded and analyzed. Acceleration at impact ranged from 24.1g to 33.3g for 1-m dives and from 31.6g to 38.4g for 3-m dives. Simple main effects were observed for dive type (p > .001) and dive distance (p > .001). The current data suggest diving athletes experience considerable head acceleration, yet more research is needed to understand the potential implications.
Aaron D. Sciascia, Arthur J. Nitz, Patrick O. McKeon, Jennifer Havens, and Timothy L. Uhl
Athletic preinjury function is typically determined via subjective recall; however, obtaining preinjury function before injury occurs should be attempted in order to establish an individual baseline for postinjury comparison. The purpose of this study was to obtain preinjury baseline values for the Foot and Ankle Disability Index (FADI) and Foot and Ankle Disability Index sport version (FADISP), single-leg hop for distance, and Star Excursion Balance Test anterior reach and determine if athletes returned to those values following ankle injury. Out of 41 qualifying injuries, FADI/FADISP scores were significantly reduced at initial injury compared with baseline and all other time points (p < .001) but recovered by discharge. Single-leg hop and Star Excursion Balance Test recovered to baseline values by the discharge time point (p ≥ .98). Subjective and objective preinjury function can be reestablished by discharge from supervised treatment following low-grade ankle injury and maintained for at least 6 months following the cessation of treatment. However, testing metrics should be reviewed on an individual athlete basis, because group data may mask individual patient needs.
Leah M. Balsamo, Kenneth P. Clark, Katherine E. Morrison, and Nicole M. Cattano
Context: Medial tibial stress syndrome (MTSS) is an overuse injury studied in endurance (ED) runners with minimal data on sprint (SP) athletes. Incorporating patient-reported outcome measures (PROMs) into clinical practice with running athletes may provide an objective way to track and treat MTSS. Purpose: To investigate PROMs as a means to monitor MTSS and general wellness in all running (i.e., ED and SP) track athletes during a competitive season. Results: The PROMs overall showed few MTSS symptoms and good global health (mean MTSS score: 0.35 ± 0.85, mean Global Health score: 33.6 ± 3.5). Sprinters reported significantly poorer MTSS scores and Global Health scores (0.544, 95% confidence interval, CI, [0.370, 1.050], p = .04]; 32.50, 95% CI [30.84, 34.16], p = .028) than ED runners (0.04, 95% CI [0.000, 0.041]; 35.5, 95% CI [33.29, 37.65]). There was a main deteriorating effect over time for the MTSS score (p = .047). Conclusions: Sprinters reported more symptoms than ED runners and need to be further researched as an independent population. The PROMs may be useful in tracking symptoms and modifying practices for individual track athletes.
Robert C. Lynall, Rachel S. Johnson, Landon B. Lempke, and Julianne D. Schmidt
Context: Reaction time is commonly assessed postconcussion through a computerized neurocognitive battery. Although this measure is sensitive to postconcussion deficits, it is not clear if computerized reaction time reflects the dynamic reaction time necessary to compete effectively and safely during sporting activities. Functional reaction time assessments may be useful postconcussion, but reliability must be determined before clinical implementation. Objective: To determine the test–retest reliability of a functional reaction time assessment battery and to determine if reaction time improved between sessions. Design: Cohort. Setting: Laboratory. Participants: Forty-one participants (21 men and 20 women) completed 2 time points. Participants, on average, were 22.5 (2.1) years old, 72.5 (11.9) cm tall, had a mass of 71.0 (13.7) kg, and were mostly right leg and hand dominant (92.7%). Interventions: Participants completed 2 clinical reaction time tests (computerized Stroop and drop stick) and 5 functional reaction time tests (gait, jump landing, single-leg hop, anticipated cut, and unanticipated cut) across 2 sessions. Drop stick and functional reaction time assessments were performed in single (motor task only) and dual task (motor task with cognitive task). Main Outcome Measures: Reaction time (in seconds) was calculated during all assessments. Test–retest reliability was determined using 2-way mixed-effects intraclass correlation coefficients (3, k). Paired samples t tests compared mean reaction time between sessions. Results: Test–retest reliability was moderate to excellent for all reaction time outcomes (intraclass correlation coefficients [3, k] range = .766–.925). Several statistically significant between-session mean differences were observed, but effect sizes were negligible to small (d range = 0.05–0.44). Conclusions: The functional reaction time assessment battery displayed similar reliability to the standard computerized reaction time assessment battery and may provide important postinjury information, but more research is needed to determine clinical utility.
Emma F. Zuk, Gyujin Kim, Jacqueline Rodriguez, Brandon Hallaway, Amanda Kuczo, Shayna Deluca, Kirsten Allen, Neal R. Glaviano, and Lindsay J. DiStefano
Clinical Scenario: Patellofemoral pain (PFP) is characterized by general anterior knee pain around the patella and is one of the most prevalent knee conditions. PFP is challenging to treat due to a wide range of contributing factors and often has chronic, reoccurring symptoms. Traditional treatment focuses on quadriceps and gluteal strengthening with minimal emphasis on deep trunk musculature. Recently, there has been a growing body of literature supporting the beneficial effects of core stability exercises as a treatment option for PFP. Clinical Question: Are core stability exercises coupled with traditional rehabilitation more effective than only traditional rehabilitation techniques for decreasing pain in patients with PFP? Summary of Key Findings: Three articles met the inclusion criteria and investigated core strengthening exercises as a treatment for PFP. Two studies investigated a 4-week exercise protocol and demonstrated a greater decrease in pain when compared to the control group. The third study examined the effects of a 6-week program where both the intervention and control groups resulted in similar reduction of pain. All articles included received a minimum of 6 on the PEDro scale. Clinical Bottom Line: There is evidence that supports core stability exercise protocols coupled with traditional rehabilitation as being more effective in reducing pain in patients with PFP when compared to traditional rehabilitation alone. Strength of Recommendation:The grade of A is recommended based on the Strength of Recommendation Taxonomy.