Greater Short-Time Recovery of Peripheral Fatigue After Short- Compared With Long-Duration Time Trial

Neuromechanical Differences between Pronated and Supinated Forearm Positions during Upper-Body Wingate Tests

Arm-cycling is a versatile exercise modality with applications in both athletic enhancement and rehabilitation, yet the influence of forearm orientation remains understudied. Thus, this study aimed to investigate the impact of forearm position on upper-body arm-cycling Wingate tests. Fourteen adult males (27.3 ± 5.8 years) underwent bilateral assessments of handgrip strength in standing and seated positions, followed by pronated and supinated forward arm-cycling Wingate tests. Electromyography (EMG) was recorded from five upper-extremity muscles, including anterior deltoid, triceps brachii lateral head, biceps brachii, latissimus dorsi, and brachioradialis. Simultaneously, bilateral normal and propulsion forces were measured at the pedal-crank interface. Rate of perceived exertion (RPE), power output, and fatigue index were recorded post-test. The results showed that a pronated forearm position provided significantly (p < 0.05) higher normal and propulsion forces and triceps brachii muscle activation patterns during arm-cycling. No significant difference in RPE was observed between forearm positions (p = 0.17). A positive correlation was found between seated handgrip strength and peak power output during the Wingate test while pronated (dominant: p = 0.01, r = 0.55; non-dominant: p = 0.03, r = 0.49) and supinated (dominant: p = 0.03, r = 0.51; don-dominant: p = 0.04, r = 0.47). Fatigue changed the force and EMG profile during the Wingate test. In conclusion, this study enhances our understanding of forearm position's impact on upper-body Wingate tests. These findings have implications for optimizing training and performance strategies in individuals using arm-cycling for athletic enhancement and rehabilitation.

Kinesio Taping Increases Peak Torque of Quadriceps Muscle After Arthroscopic Meniscectomy, Double-Blinded RCT

Purpose

This study was conducted to release the debate and examine the short-term impact of KT on the quadriceps muscle following arthroscopic surgery for partial meniscectomy.

Patients and Methods

As part of a double-blind, randomized controlled trial, 40 people who had an arthroscopic partial meniscectomy (APM) were randomly put into two groups, A and B. Group A received Kinesio tape (KT) for the superficial heads of the quadriceps muscle, while group B received placebo KTk. After 10 minutes of KT application, the peak torque of both groups was measured using a Biodex isokinetic dynamometer.

Results

Peak torque showed a significant increase in group A in comparison with group B during angular velocity 60◦/Sec. (F (1, 130) = 58.9, p <0.001, ƞ2 =0.31) and during angular velocity 180◦/Sec. (F (1, 38) = 25.0, p <0.001, ƞ2 =0.40).

Conclusion

After APM, individuals experienced an immediate and significant improvement in the quadriceps' peak torque following KT application to the Rectus femoris, Vastus medialis, and Vastus lateralis muscles from origin to insertion.

Determinants of whole-body maximal aerobic performance in young male and female athletes: The roles of lower extremity muscle size, strength and power

This study sought to determine whether lower extremity muscle size, power and strength could be a determinant of whole-body maximal aerobic performance in athletes. 20 male and 19 female young athletes (18 ± 4 years) from various sporting disciplines participated in this study. All athletes performed a continuous ramp-incremental cycling to exhaustion for the determination of peak oxygen uptake (V˙O2peak: the highest V˙O2 over a 15-s period) and maximal power output (MPO: power output corresponding to V˙O2peak). Axial scanning of the right leg was performed with magnetic resonance imaging, and anatomical cross-sectional areas (CSAs) of quadriceps femoris (QF) and hamstring muscles at 50% of thigh length were measured. Moreover, bilateral leg extension power and unilateral isometric knee extension and flexion torque were determined. All variables were normalised to body mass, and six independent variables (V˙O2peak, CSAs of thigh muscles, leg extension power and knee extension and flexion torque) were entered into a forward stepwise multiple regression model with MPO being dependent variable for males and females separately. In the males, V˙O2peak was chosen as the single predictor of MPO explaining 78% of the variance. In the females, MPO was attributed to, in the order of importance, V˙O2peak (p < 0.001) and the CSA of QF (p = 0.011) accounting for 84% of the variance. This study suggests that while oxygen transport capacity is the main determinant of MPO regardless of sex, thigh muscle size also has a role in whole-body maximal aerobic performance in female athletes.

Maximal results with minimal stimuli: the fewest high-frequency pulses needed to measure or model prolonged low-frequency force depression in the dorsiflexors

Quantifying prolonged low-frequency force depression (PLFFD) with the gold-standard 1-s trains presents challenges, so paired pulses have been used. Owing to greater impairment of high-frequency doublet than tetanic torque, paired pulses underestimate PLFFD. This study aimed to approximate the minimum number of high-frequency pulses needed to avoid such underestimation and assess the feasibility of modeling PLFFD from a limited number of experimental pulses. In 13 participants, a 1-s 10-Hz train and 100-Hz trains with 2, 4, 7, 12, 15, 25, 50, or 100 pulses were evoked before and after (15 min, 2, 4, and 7 days) eccentric exercise of the dorsiflexors. With ≤12 pulses, impairment of 100-Hz torque was greater than the 1-s train (P ≤ 0.05; e.g., 12 vs. 100 pulses at 4 days: 97.8 ± 8.5% vs. 100.5 ± 8.2% baseline). Consequently, with ≤12 pulses, PLFFD was underestimated compared with the gold-standard measure (P ≤ 0.05; e.g., 12 vs. 100 pulse 10:100-Hz torque ratio at 4 days: 86.8 ± 12.8% vs. 84.6 ± 13.5% baseline). Modeling reproduced 10:100-Hz ratios (PLFFD) with 95% limits of agreement of -13.6% to 16.7% of experimental values with ≥12 pulses. Our results indicate that a minimum of 13-25 pulses of 100 Hz are needed to accurately quantify PLFFD in the dorsiflexors. Although this may not be the minimum range for other muscles, a similar relationship with pulse number likely exists. Modeling may eventually provide an option to estimate PLFFD from experimental trains with relatively few pulses; however, further development is imperative to reduce variability.NEW & NOTEWORTHY Ideally, prolonged low-frequency force depression (PLFFD) is measured with 1-s trains of supramaximal stimuli; however, this induces considerable discomfort. We tested briefer trains to approximate the minimum number of high-frequency pulses needed to accurately determine PLFFD and the feasibility of modeling 1-s tetani with relatively few pulses. After eccentric exercise, 13-25 high-frequency pulses were needed to accurately measure PLFFD. Modeling reproduced mean experimental values but had considerable variability.