The purpose of the current study was to investigate the effects of finger strength training (ST) on finger strength, independence, force control, and adaptations in multifinger coordination. Thirty-three healthy, young (23.0 ± 2.9 years) subjects were randomly assigned into 4 groups. Group 1 (G1) trained all fingers together, Group 2 (G2) trained individual fingers without restricting movements of the non-training fingers, and Group 3 (G3) trained individual fingers while restricting the movement of the nontraining fingers. The control group (G0) did not undergo any training. A vertically hanging load was attached to a spring that passed through a pulley. The other end of the string extended to the horizontal plane and had thimbles attached to it. Subjects were asked to rest their forearm on the table and lift the load by inserting their fingers into the thimbles. The training protocol lasted 6 weeks. Identical experimental tests were conducted 4 times, biweekly, across the 6-week training. Force coordination and moment coordination, defined as synergies stabilizing the resultant force and the resultant moment of all finger forces, in a multifinger pressing task were quantified using the Uncontrolled Manifold (UCM) analysis. The UCM analysis allocates motor variability into two components, one in the null space of a motor task and the other perpendicular to the null space. During multifinger pressing tasks, multifinger coordination exists when the variability in the null space is greater than the variability in the subspace perpendicular to the null space. The multifinger coordination was quantified as the difference between the variance within the null space and that perpendicular to the null space, normalized by the total variance. Thus, the coordination measure in our analysis is a unitless variable. A greater coordination measure indicates better multifinger coordination. Moment-stabilizing multifinger coordination increased only in G1 (from 1.197 ± 0.004 to 1.323 ± 0.002, p < .01), and force-stabilizing coordination increased only in G3 (from 0.207 ± 0.106 to 0.727 ± 0.071, p < .01). Finger strength, measured by the maximal voluntary finger force of pressing 4 fingers, increased significantly in all training groups (from 103.7 ± 3.1 N to 144.0 ± 3.6 N for training groups, all p < .001). Finger-force errors, quantified by the deviations between the required force profiles (20% maximal voluntary force) presented to the subjects and the actual force produced, decreased significantly with ST for all the training groups (all p < .05). Finger independence also decreased significantly for all the training groups (p < .05). We conclude that the neuromuscular system adaptations to multifinger ST are specific to the training protocol being employed, yielding improvements in different types of multifinger coordination (i.e., coordination-specific ST), finger-force control, and finger strength and a decrease in finger independence. Finger independence, depending on the nature of the task, might or might not be favorable to certain task performances. We suggest that ST protocol should be carefully designed for the improvement of specific coordination of multieffector motor systems.
Jae Kun Shim, Jeffrey Hsu, Sohit Karol, and Ben F. Hurley
allowed, whereas in the later punching techniques are allowed but much less executed than kicking techniques), resulting in a very specific work-to-rest ratio 3 – 8 and physiological demands. 9 – 13 Therefore, the training process for each combat sports must be tailored for its demands. 11 , 12 , 14 To
Milos R. Petrovic, Amador García-Ramos, Danica N. Janicijevic, Alejandro Pérez-Castilla, Olivera M. Knezevic, and Dragan M. Mirkov
–V relationship during sport-specific tasks such as climbing 12 or sprinting. 13 Kayak sprint racing has been in the Olympic Games program since 1936. The standard discipline distances are 200, 500, and 1000 m. Nowadays, the shortest time race in European and World championships is K2 (2 kayakers in boat) on 200
Sandra C. Webber, Francine Hahn, Lisa M. Lix, Brenda J. Tittlemier, Nancy M. Salbach, and Ruth Barclay
continuous distance walk, time to practice specific outdoor walking skills (e.g., stopping suddenly, speeding up, walking on different surfaces), a second continuous distance walk, and a 10-min cooldown. Each week, the outdoor walking skills addressed two or more of the eight dimensions of outdoor mobility
Martin Buchheit, Mathieu Lacome, Yannick Cholley, and Ben Michael Simpson
Within the tactical periodization training approach, tactical, technical, physiological, and psychological elements are rarely trained in isolation, which is believed to improve specific motor skill acquisition and accelerate tactical learning. 1 In fact, daily training components are structured
Alyssa J. Wagner, Casey D. Erickson, Dayna K. Tierney, Megan N. Houston, and Cailee E. Welch Bacon
Eating disorders in female athletes are a commonly underdiagnosed condition. Better screening tools for eating disorders in athletic females could help increase diagnosis and help athletes get the treatment they need.
Focused Clinical Question:
Should screening tools be used to detect eating disorders in female athletes?
Summary of Key Findings:
The literature was searched for studies that included information regarding the sensitivity and specificity of screening tools for eating disorders in female athletes. The search returned 5 possible articles related to the clinical question; 3 studies met the inclusion criteria (2 cross-sectional studies, 1 cohort study) and were included. All 3 studies reported sensitivity and specificity for the Athletic Milieu Direct Questionnaire version 2, the Brief Eating Disorder in Athletes Questionnaire version 2, and the Physiologic Screening Test to Detect Eating Disorders Among Female Athletes. All 3 studies found that the respective screening tool was able to accurately identify female athletes with eating disorders; however, the screening tools varied in sensitivity and specificity values.
Clinical Bottom Line:
There is strong evidence to support the use of screening tools to detect eating disorders in female athletes. Screening tools with higher sensitivity and specificity have demonstrated a successful outcome of determining athletes with eating disorders or at risk for developing an eating disorder.
Strength of Recommendation:
There is grade A evidence available to demonstrate that screening tools accurately detect female athletes at risk for eating disorders.
Paul A. Borsa, Eric L. Sauers, and Scott M. Lephart
Functional training for the purpose of restoring dynamic joint stability has received considerable interest in recent years. Contemporary functional training programs are being designed to complement, rather than replace, traditional rehabilitation protocols. The purpose of this clinical commentary is to present a management strategy for restoring dynamic stability in the posterior cruciate ligament (PCL)-injured knee. The strategy presented integrates five key concepts: (a) planned variation of exercise, (b) outcomes-based assessment, (c) kinetic chain exercise, (d) proprioception and neuromuscular control, and (e) specificity of activity. Pertinent research findings and a clinical rationale are provided for using functional training in the restoration of dynamic stability in the PCL-injured knee.
Warren B. Young
The purposes of this review are to identify the factors that contribute to the transference of strength and power training to sports performance and to provide resistance-training guidelines. Using sprinting performance as an example, exercises involving bilateral contractions of the leg muscles resulting in vertical movement, such as squats and jump squats, have minimal transfer to performance. However, plyometric training, including unilateral exercises and horizontal movement of the whole body, elicits significant increases in sprint acceleration performance, thus highlighting the importance of movement pattern and contraction velocity specificity. Relatively large gains in power output in nonspecific movements (intramuscular coordination) can be accompanied by small changes in sprint performance. Research on neural adaptations to resistance training indicates that intermuscular coordination is an important component in achieving transfer to sports skills. Although the specificity of resistance training is important, general strength training is potentially useful for the purposes of increasing body mass, decreasing the risk of soft-tissue injuries, and developing core stability. Hypertrophy and general power exercises can enhance sports performance, but optimal transfer from training also requires a specific exercise program.
Mathieu Lacome, Ben M. Simpson, Yannick Cholley, and Martin Buchheit
small-sided games (SSGs) can be used to improve football-specific fitness and match winning–related factors. 1 – 3 The key programming elements of SSGs are now well understood: a range of variables can be modulated to affect intensity and, in turn, the metabolic and locomotor responses. 4 Nevertheless
Mark A. Sutherlin
not uncommon that the majority of PRO measures used in athletic training focus on region- or joint-specific measures. 1 This may ultimately result in PRO administration being determined by the types and frequency of injuries seen across athletes in general, or potentially influenced by injuries