Isokinetics and Exercise Science - Volume 29, issue 3

Authors: Jeon, Jeongwoo | Lee, Jiyeon | Hong, Jiheon | Yu, Jaeho | Kim, Jinseop | Lee, Dongyeop

Article Type: Research Article

Abstract: BACKGROUND: Dynamic balance is an essential factor for efficient pitching by baseball pitchers. OBJECTIVE: To compare distances reached and lower-extremity muscle activity during the star excursion balance test (SEBT) in baseball pitchers and healthy young adults. METHODS: Nineteen baseball pitchers (BPG) and 20 healthy adults (HAG) were recruited. Surface EMG was used to measure the activity of vastus medialis (VM), vastus lateralis (VL), tibialis anterior, and lateral gastrocnemius. RESULTS: The BPG exhibited greater dynamic balance than in the HAG (p < 0.05) in the posteromedial …(PM) and posterolateral (PL) directions. For the PM and PL directions, significantly greater muscle activity of VM and VL was found in the BPG than in the HAG (p < 0.05). CONCLUSION: SEBT performance is characterized by high-level VM and VL muscle activities. Neuromuscular control of knee extensors, such as the VM and VL of pitchers, might affect the dynamic balance measured by the SEBT. Show more

Keywords: Baseball pitcher, dynamic balance, star excursion balance test, electromyography, lower extremity

DOI: 10.3233/IES-203163

Citation: Isokinetics and Exercise Science, vol. 29, no. 3, pp. 327-333, 2021

Authors: Jones, Paul | Ivey, Patrick | Skutnik, Ben | Cocco, Adam R. | Colborn, Chris E. | Daily, Jennifer P. | Caruso, John F.

Article Type: Research Article

Abstract: BACKGROUND: Global positioning system (GPS) data, when obtained from athletes offers unique information on their performance. Given the information GPS data provides, it is important to identify data most pertinent to an athlete’s performance. OBJECTIVE: We evaluated a GPS-based running quality variable to predict the variance in total player load (TPL) and player load per minute (PLPM) from female soccer player (n = 26) data. METHODS: Running quality was the ratio of the displacement per minute to total distance covered. TPL was quantified as the sum of velocity …change rates in all three planes of motion, while PLPM was a ratio of load generated per minute of activity. RESULTS: With a logarithmic transformation of TPL data, a Pearson Product Moment Correlation analysis revealed running quality accounted for significant (r = - 0.65) amounts of our criterion’s variance, which implied higher running quality led to lower log (TPL) values. With PLPM as our dependent variable, running quality correlated with significant (r = 0.63) amounts of our criterion’s variance. CONCLUSIONS: Movement efficiency appears to be an important contributor to our correlations. We suggest running quality be examined as a correlate to performance in other sports in which running is crucial to success. Show more

Keywords: Global positioning system, soccer, efficiency

DOI: 10.3233/IES-203159

Citation: Isokinetics and Exercise Science, vol. 29, no. 3, pp. 335-341, 2021

Authors: Özgünen, Kerem | Özdemir, Çiğdem | Adaş, Ümüt | Kilci, Abdullah | Boyraz, Cumhur | Eryilmaz, Selcen Korkmaz | Günaşti, Özgür | Askeri, Nedim | Kurdak, Sadi

Article Type: Research Article

Abstract: BACKGROUND: Sprint drills are part of the soccer training routine for their resemblance to match activities. There is a lack of information in the literature about the changes in isokinetic skeletal muscle strength in response to sprint training. OBJECTIVE: This study evaluates the effects of eight weeks, on-season repeated sprint training with a change of direction on isokinetic strength parameters in well-trained youth soccer players. METHODS: Nineteen well-trained youth soccer players volunteered to participate in the study. The training program included three sets of six, 40 m (20 + 20 …m) shuttle sprints twice a week for eight weeks. Isokinetic peak moment, work, and power of knee extensors and flexors were measured at angular velocities of 60, 180 and 240 ∘ /s. Pre- and post-training valid isokinetic sector data were compared. RESULTS: Following the training period, dominant and non-dominant legs’ peak moment, work, and power values for both extensor and flexor muscle groups improved significantly at various angular velocities. CONCLUSIONS: Isokinetic strength enhancement may be explained with the induction of muscle hypertrophy following a prolonged period of sprint training. Show more

Keywords: Muscle strength, valid isokinetic sector

DOI: 10.3233/IES-202231

Citation: Isokinetics and Exercise Science, vol. 29, no. 3, pp. 343-351, 2021