Machado, W, Paz, G, Mendes, L, Maia, M, Winchester, JB, Lima, V, Willardson, JM, and Miranda, H. Myoeletric activity of the quadriceps during leg press exercise performed with differing techniques. J Strength Cond Res 31(2): 422-429, 2017-The quadriceps muscle supplies the motive force for dynamic knee extension. During this action, the vastus medialis oblique (VMO) and vastus lateralis (VL) co-contract to stabilize the patella as it tracks within the patellofemoral groove. The purpose of this study was to analyze surface electromyographic (SEMG) responses for the VL, VMO, rectus femoris (RF), and biceps femoris (BF), as well as the VMO:VL ratio during an open-kinetic chain 45° angled leg press (LP45). The traditional LP45 technique was compared with 2 alternative LP45 exercise techniques that used a physioball and elastic band, respectively. Thirteen female college students performed 3 protocols in random order: TRAD-1 LP45 set performed using the traditional exercise technique, PBALL-1 LP45 set performed with a physioball held between the knee joints, and PEB-1 LP45 set performed with an elastic band proximal to the knee joints. Ten repetitions at 70% of a 10 repetition maximum load were performed in each protocol, and the SEMG data were recorded for the VMO, VL, RF, and BF muscles. Significant increases in VMO activity were noted during PBALL vs. PEB (p = 0.001) and TRAD (p = 0.002). Higher VMO activity was noted during TRAD vs. PEB (p = 0.001). Greater VL activity was noted during PBALL vs. TRAD (p = 0.0001) and PEB (p = 0.0001). The PBALL condition elicited a greater VMO:VL ratio during the concentric phase vs. the PEB (p = 0.001) and TRAD (p = 0.001) protocols. Greater RF activity was observed during PEB vs. TRAD (p = 0.001) and PBALL (p = 0.001). Therefore, practitioners should consider placing a physioball between the knees during the LP45 exercise as an alternative technique when greater overall quadriceps activity is desired for clinical rehabilitation or a muscle strengthening program.

Purpose. To compare the effects of aquatic and land plyometric training on the vertical jump (VJ) and delayed onset muscle soreness (DOMS) in soccer players. Methods. Twenty-four male soccer players aged 16-18 years (16.53 ± 0.5 years) were randomly divided into three groups: aquatic plyometric training (APT) (n = 8; age: 16.4 ± 0.4 years; body mass: 68.3 ± 7.54 kg; height: 179.75 ± 8.13 cm); land plyometric training (LPT) (n = 8; age: 16.5 ± 0.5 years; body mass: 68.2 ± 7.8 kg; height: 177.0 ± 7.4 cm); and control group (n = 8; age: 16.7 ± 0.6 years; body mass: 61.2 ± 6.5 kg; height: 171.43 ± 5.75 cm), not performing any jump program. An identical training program was applied for 6 weeks, totalling 944 jumps. The VJ was evaluated on a leap jump platform and the Visual Analogue Scale measured the change in DOMS perception.Results. There was a significant increase in the VJ height in both experimental groups (LPT and APT) (p < 0.05). A significant reduction in DOMS perception was verified for the APT group in comparison with the LPT group (p < 0.05) between the first and last week of training. The foot contact time significantly decreased (p < 0.05) in the APT group from pre-to posttest. Significant improvements (p < 0.05) were observed in the flight time and jump speed from pre-to post-test in both LPT and APT groups. Conclusions. APT can increase the VJ height and reduce DOMS perception in soccer players.

Therefore, both physioball and elastic band can be adopted during LP with the goal to reduce excessive varus and valgus forces, respectively, even performing consecutive sets with submaximal loads. Furthermore, this may be an interesting alternative to increasing quadriceps activation and improving the knee joint stabilization.

Introduction: This study evaluated the degree of disability, pain levels, muscle strength, and electromyographic function (RMS) in individuals with leprosy. Methods: We assessed 29 individuals with leprosy showing common peroneal nerve damage and grade 1 or 2 disability who were referred for physiotherapeutic treatment, as well as a control group of 19 healthy participants without leprosy. All subjects underwent analyses of degree of disability, electromyographic tests, voluntary muscle force, and the Visual Analog Pain Scale. Results: McNemar's test found higher levels of grade 2 of disability (∆ = 75.9%; p = 0.0001) among individuals with leprosy. The Mann-Whitney test showed greater pain levels (∆ = 5.0; p = 0.0001) in patients with leprosy who had less extension strength in the right and left extensor hallucis longus muscles (∆ = 1.28, p = 0.0001; ∆ = 1.55, p = 0.0001, respectively) and dorsiflexion of the right and left feet (∆ = 1.24, p = 0.0001; ∆ = 1.45, p = 0.0001, respectively) than control subjects. The Kruskal-Wallis test showed that the RMS score for dorsiflexion of the right (∆ = 181.66 m·s -2 , p = 0.001) and left (∆ = 102.57m·s -2 , p = 0.002) feet was lower in patients with leprosy than in control subjects, but intragroup comparisons showed no difference. Conclusions: Leprosy had a negative influence on all of the study variables, indicating the need for immediate physiotherapeutic intervention in individuals with leprosy. This investigation opens perspectives for future studies that analyze leprosy treatment with physical therapeutic intervention.

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Os métodos de treinamento de força são aplicados através da manipulação das variáveis metodológicas, que podem modificar as características do treinamento. Dessa forma, o objetivo do presente estudo foi investigar o efeito do método de séries pareadas de agonista-antagonista (PAA) versus o método tradicional (MT) sobre o volume total de treinamento (VTT) ou eficácia, a eficiência (VTT/tempo) e o sinal eletromiográfico (EMG). Participaram do estudo 10 sujeitos treinados (22,4 ± 0,9 anos, 173 ± 5 cm, 74,8 ± 7,8kg, 13,1 ± 2,3% gordura corporal). No MT foram realizadas 3 séries no exercício de supino vertical (SV) e, em seguida, 3 séries na remada aberta (RA). No PAA foram realizadas 3 séries pareadas entre o SV e RA. Foram adotados dois minutos de intervalo entre as séries em ambos os protocolos. Os sinais de EMG do latíssimo do dorso (LD), porção clavicular do peitoral maior (PMC), bíceps braquial (BB) e tríceps braquial cabeça longa (TBL) foram coletados durante a RA. Para as comparações entre os protocolos e séries aplicou-se a ANOVA two-way e post hoc de Bonferroni adotando-se p < 0,05. Verificou-se aumento significativo no VTT no PAA comparado ao MT. A atividade EMG dos músculos LD e BB foi significativamente maior no PAA em comparação ao MT. Em relação ao PMC e TBL, verificou-se redução significativa no PAA comparado ao MT. Logo, o PAA parece ser uma opção interessante em programas que visam aumento no VTT, bem como, economia de tempo (eficiência) sem comprometer o desempenho muscular.

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SummaryStudy aim: To determine and compare the time under tension (TUT) required to perform 8, 10 and 12 repetition maximum (RM) loads in the bench press exercise. Material and methods: Twenty men (24.17 ± 4.69 years) were selected intentionally and properly. We included in the study physically active individuals, with a weekly frequency of physical activity of at least two days for six months, and excluded individuals with injury or pain that could interfere with the correct execution of the exercise and individuals with positive PAR-Q. The 10-RM test consisted in performing ten consecutive repetitions with maximum overload and the highest speed in bench press exercise on the Smith machine. After 48 h, 10-RM sets were performed with the load obtained in the 10-RM load testing. The TUT in 10-RM was verified through kinematics using the timing technique of the Kinovea software. Results: The RM loads and TUT obtained during the retest session showed normal distribution between subjects. However, no significant differences were found between the loads 8, 10 and 12-RM within and between subjects (p < 0.05). The verified TUT showed a difference from 8 to 10-RM and from 8 to 12-RM, but no significant difference was found between TUT protocols for 10 and 12-RM (p < 0.05). Conclusion:The study results enable evaluation of TUT in bench press exercise on the Smith machine for the study sample, allowing, for this group, the prediction and control of training intensity through the TUT.