Marcelo Bannwart Santos

Influence of knee position on the postural stability index registered by the Biodex Stability System

The importance of knee position for bodily stability is described by some authors, however Biodex Stability System (BSS) trials have not been used to assess the reliability and effects of different knee positions. The purposes of this study were to test the reliability of BSS indices using two knee positions in the measurement protocol (either permitting slight knee flexion or maintaining them locked in total extension) and to compare the BSS indices between these two knee positions. The measurements were taken of the Overall Stability Index (OSI), Anterior-Posterior Stability Index (APSI) and Medial-Lateral Stability Index (MLSI) during a 30s protocol which gradually and automatically increased in difficulty among 21 healthy female subjects (22.8+/-1.0 years old). The subjects performed four trials which, without visual feedback, permitted knee flexion as well as four trials which did not, in a randomized order. The first two trials in each set were used for familiarization only. Permitting slight flexion yielded better reliability results (OSI Intra-class Correlation Coefficient [ICC]=0.93, APSI ICC=0.90, MLSI ICC=0.89) than maintaining the knee in total extension (OSI ICC=0.88, APSI ICC=0.87, MLSI ICC=0.79), with good agreement in the Bland and Altman test. Moreover, permitted knee flexion in BSS presented better balance stability values for OSI (P=0.001) and APSI (P=0.024), however the MLSI did not present significant difference between positions (P=0.345).

Swimmer's shoulder in young athlete: rehabilitation with emphasis on manual therapy and stabilization of shoulder complex.

Competitive swimmers swim10e14kmperday six to sevendays per week, which corresponds to 2500 rotations of the shoulder per day. The combination of these repetitive movements with a large rangeofmotionof the jointmakes the shouldermoreprone to injury in this sport (Stockeret al.,1995; Pink andTibone, 2000;Weldon and Richardson, 2001; Lynch et al., 2010).Wolf et al. (2009) investigated a university swim team over five seasons and found that 71% of the athletes became injured in this period,with the shoulder accounting for 35.4% of all injuries. Another study involving young highperformance athletes reports that 91% of the 80 athletes analyzed had shoulder pain (Sein et al., 2010). “Swimmer’s shoulder” was first described by Kennedy and Hawkins (1974), who defined the condition as a painful presentation due to repetitive impingement of the shoulder in swimmers. Swimmer’s shoulder does not have an established clinical diagnosis, but rather is a syndrome that may be due to subacromial impingement, tendinopathy of the rotator cuff and long portion of the biceps brachii, shoulder instability, labral tear or acromion-clavicle injury

Associação do valgo dinâmico do joelho no teste de descida de degrau com a amplitude de rotação medial do quadril

INTRODUCTION: The knee is a widely studied joint due to its high incidence of injuries. Most studies correlate these lesions with the valgus during flexion of the knee (dynamic), which is attributed mainly to the poor performance of the gluteus medius muscle. OBJECTIVE: This study had the aim to evaluate the association between the hip medial rotation and the valgus angle (in two dimensions) during the stair descent test obtained through photogrammetry (SAPO software). METHODS: 104 female volunteer athletes were evaluated in the measurement of the hip internal rotation (Craigs test) and the angle value of knee valgus during the descending of a step; the analyses were submitted to inter-rater reliability assessment observed with the Bland and Altman plot. The data were analyzed through multiple linear regression in order to adjust the results to the age of the evaluees. RESULTS: The angle generated in the medial rotation of the hip presented average of 45.3 degrees, with the increase of the knee valgus, while the valgus during the descent movement presented average of 8.6 degrees. Significant inverse relation in the association of the medial rotation and knee valgus was found. CONCLUSION: The presented data show a possible association between the reduction of the medial rotation of the hip with the increase of the knee valgus; however, the data are not conclusive since the evaluation was bidimensional. The obtained results suggest the need of more conclusive studies.

Modulation of isometric quadriceps strength in soccer players with transcranial direct current stimulation: a crossover study.

Abstract Vargas, VZ, Baptista, AF, Pereira, GOC, Pochini, AC, Ejnisman, B, Santos, MB, João, SMA, and Hazime, FA. Modulation of isometric quadriceps strength in soccer players with transcranial direct current stimulation: a crossover study. J Strength Cond Res 32(5): 1336–1341, 2018—The aim of this study was to evaluate the effect of transcranial direct current stimulation (tDCS) on the maximum isometric muscle contraction (MVIC) of the knee extensors in soccer players at the preprofessional level. Twenty female soccer players aged 15–17 years (mean = 16.1; SD = 0.9) with 5.2 ± 2.6 years of training were randomly divided into 2 groups to receive either active or sham tDCS in a single session (2 mA; 0.057 mA·cm−2). The MVIC of the knee extensors was evaluated in both lower limbs by manual dynamometry in 5 sets of contractions divided into 4 blocks: (a) prestimulation, (b) during tDCS, (c) 30 minutes after tDCS, and (d) 60 minutes after tDCS. After an interval of 7 days, the groups were evaluated again, and the type of initial stimulation was inverted between participants. The MVIC of the knee extensors increased significantly during active tDCS (dominant limb (DL) = 0.4; IC = 0.1–0.8 N·Kg−1), 30 minutes after active tDCS (DL = 0.9; IC 0.4–1.4 N·Kg−1), and 60 minutes after active tDCS (DL = 1.0; IC 0.3–1.6 N·Kg−1) but not for sham tDCS. Our conclusion was that tDCS temporarily increases isometric quadriceps strength in adolescent female soccer players, which may be useful for both strength training and rehabilitation.