Maximal Isometric Handgrip Strength (HGS) In Gr...

Reduction of muscle strength in people with Parkinson has been reported repeatedly [10]. Dopaminergic deficits in people with Parkinson reduce stimulation in the motor cortex, which can affect the use of motor unit and lead to muscle weakness [11]. Arm muscle function involves manipulating objects that require the use and integration of muscle activity from the shoulder to the fingers. Evidence suggests that people with Parkinson have weaknesses in some muscle groups, especially the wrists and elbows; even when allowance is made for the slow development of maximal force [12]. A non-invasive and inexpensive method widely used to assess muscle strength is handgrip strength (HGS). This measurement is a reflection of the maximum isometric strength of the muscles of the hand and forearm [13]. HGS is often used as an indicator of measuring muscle strength of the whole body and is considered a practical, fast, easy and independent tool for the observer [14]. However, there is little research on the association of HGS in Parkinson disease; but in general, HGS is lower in people with Parkinson than in healthy people [15].

Maximal Isometric Handgrip Strength (HGS) in Gr...

Cross-sectional area (CSA) and mean EI of the right rectus femoris were measured by ultrasound to evaluate the quantity and quality of the muscle, respectively. Physical function was measured by handgrip strength (HGS), gait speed, sit-to-stand 60 s (STS-60) test, and instrumental activities of daily living (IADL) scale.

Therefore, the evaluation of upper body muscular strength seems to be a good strategy to predict an athlete's performance. In this sense, isokinetic evaluation, that provides reliable and reproducible data77 Brown LE, Whitehurst M, Findley BW. Reliability of rate of velocity development and phase measures on an isokinetic device. J Strength Cond Res 2005;19(1):189-92., has been used as a method to assess upper extremities strength (i.e. peak torque - PT) in combat sports such as judo88 Janiak J, Krawczyk B. Relationship between muscle force and total or lean body mass in highly experienced combat athletes. Biol Sport 1995;12(2):107-11.,99 Busko K, Nowak A. Changes of the maximal muscle torque and maximal power output of lower extremities in male judoist during training. Hum Mov 2008;9(2):111-5., boxing88 Janiak J, Krawczyk B. Relationship between muscle force and total or lean body mass in highly experienced combat athletes. Biol Sport 1995;12(2):107-11.,1010 Pedzich W, Mastalerz A, Sadowski J. Estimation of muscle torque in various combat sports. Acta Bioeng Biomech 2012;14(4):107-112., and taekwondo1010 Pedzich W, Mastalerz A, Sadowski J. Estimation of muscle torque in various combat sports. Acta Bioeng Biomech 2012;14(4):107-112.. However, the most common assessment used to measure strength in JJ athletes is handgrip strength (HSG)11 Andreato LV, De Moraes SM, Gomes TLM, Esteves JV, Andreato TV, Franchini E. Estimated aerobic power, muscular strength and flexibility in elite Brazilian Jiu Jitsu athletes. Sci Sports 2011;26(6):329-37.,33 Oliveira M, Moreira D, Godoy JRP, Cambraia AN. Avaliação da força de preensão palmar em atletas de jiu-jitsu de nível competitivo. Rev Bras Cienc Mov 2006;14(3):63-70.,1111 Andreato LV, Franchini E, De Moraes SM, Pastório JJ, Da Silva DF, Esteves JV, et al. Physiological and technical-tactical analysis in Brazilian jiu-jitsu competition. Asian J Sports Med 2013;4(2):137-143.. As it has been shown elsewhere66 Silva BVC, Marocolo Junior M, Simim MAM, Franchini E, Mota GR. Performance in kimono grip strength tests among Brazilian Jiu Jitsu practitioners from different levels. J Comb Sports Mart Arts 2014;5(2):11-15.,1212 Franchini E, Souza CEB, Urasaki R, Oliveira RSF, Sauressig F, Matheus L. Teste de resistência de força isométrica e dinâmica na barra com o judogi. Proceeding of III Congreso de La Associasión Espanõla de Ciencias Del Deporte: 2004., HSG does not represent strength demands during a combat. In addition, protocols used can affect values registered1313 Roberts HC, Denison HJ, Martin HJ, Patel HP, Cyrus HS, Cooper C, Sayer AA. A review of the measurement of grip strength in clinical and epidemiological studies: towards a standardized approach. Age Ageing 2011;40(4):423-9..

As an alternative method to evaluate judo athletes' upper body strength, a specific test was proposed - Kimono Grip Strength Tests (KGST)1212 Franchini E, Souza CEB, Urasaki R, Oliveira RSF, Sauressig F, Matheus L. Teste de resistência de força isométrica e dinâmica na barra com o judogi. Proceeding of III Congreso de La Associasión Espanõla de Ciencias Del Deporte: 2004.,1414 Franchini E, Miarka B, Matheus L, Del Vecchio FB. Endurance in judogi grip strength tests: Comparison between elite and non-elite judo players. Arch Budo 2011;7(1):1-4. . KGST are composed of two tests: maximal static lift (MSL) and maximal number of repetitions (MNR). Both tests have been used to verify the physical components that determine the ability to maintain the grip (i.e., isometric and dynamic strength endurance)1414 Franchini E, Miarka B, Matheus L, Del Vecchio FB. Endurance in judogi grip strength tests: Comparison between elite and non-elite judo players. Arch Budo 2011;7(1):1-4.. Recently, KGTS have been successfully used to discriminate JJ athletes of different competitive levels66 Silva BVC, Marocolo Junior M, Simim MAM, Franchini E, Mota GR. Performance in kimono grip strength tests among Brazilian Jiu Jitsu practitioners from different levels. J Comb Sports Mart Arts 2014;5(2):11-15.,1515 Silva BVC, Junior MM, Simim MAM, Rezende FN, Franchini E, Mota GR. Reliability in kimono grip strength tests and comparison between elite and non-elite Brazilian Jiu Jitsu players. Arch Budo 2012;8(2):91-5.,1616 Silva BVC, Marocolo Junior M, Rogério FC, Dias IS, Simim MAM, Mota GR. Testes físicos discriminam praticantes de Brazilian Jiu-Jitsu? Rev Bras Cienc Mov 2014;22(1):92-8.. Additionally, these tests present high reliability1515 Silva BVC, Junior MM, Simim MAM, Rezende FN, Franchini E, Mota GR. Reliability in kimono grip strength tests and comparison between elite and non-elite Brazilian Jiu Jitsu players. Arch Budo 2012;8(2):91-5..

On a different day, after general and specific warm up procedures previously described66 Silva BVC, Marocolo Junior M, Simim MAM, Franchini E, Mota GR. Performance in kimono grip strength tests among Brazilian Jiu Jitsu practitioners from different levels. J Comb Sports Mart Arts 2014;5(2):11-15.,1414 Franchini E, Miarka B, Matheus L, Del Vecchio FB. Endurance in judogi grip strength tests: Comparison between elite and non-elite judo players. Arch Budo 2011;7(1):1-4.,1616 Silva BVC, Marocolo Junior M, Rogério FC, Dias IS, Simim MAM, Mota GR. Testes físicos discriminam praticantes de Brazilian Jiu-Jitsu? Rev Bras Cienc Mov 2014;22(1):92-8., athletes performed the two KGST (MSL and MNR) both gripping a kimono wrapped around a bar. First, athletes performed the MSL, defined as the time that the subject was able to sustain his own weight at maximal elbow flexion66 Silva BVC, Marocolo Junior M, Simim MAM, Franchini E, Mota GR. Performance in kimono grip strength tests among Brazilian Jiu Jitsu practitioners from different levels. J Comb Sports Mart Arts 2014;5(2):11-15.,1414 Franchini E, Miarka B, Matheus L, Del Vecchio FB. Endurance in judogi grip strength tests: Comparison between elite and non-elite judo players. Arch Budo 2011;7(1):1-4.. After a 15 min rest period, participants completed the MNR, which consisted of performing a maximum number of repetitions from elbow fully extended to elbow fully flexed, using the same grip as applied during MSL66 Silva BVC, Marocolo Junior M, Simim MAM, Franchini E, Mota GR. Performance in kimono grip strength tests among Brazilian Jiu Jitsu practitioners from different levels. J Comb Sports Mart Arts 2014;5(2):11-15.,1414 Franchini E, Miarka B, Matheus L, Del Vecchio FB. Endurance in judogi grip strength tests: Comparison between elite and non-elite judo players. Arch Budo 2011;7(1):1-4..

Despite the isometric pattern of the MSL, it seems that the highest correlation observed was not with MVIC, but with eccentric dynamic contractions, both for elbow flexors (Table 3) and extensors (Table 4). In fact, there was a very large correlation of MVIC of elbow flexors at 45, disputing the idea that the most specific joint angle (120) in the dynamometer would present the largest level of correlation. Nevertheless, levels of correlation of all MVIC were apparently lower than those obtained at eccentric mode. Tendency analysis during the execution of MSL (while athletes sustained their own body mass) revealed a clear effort to avoid eccentric contraction of elbow flexors and shoulder extensors, while maintaining isometric position at the maximum flexion elbow angle. Therefore, even with the isometric aspect of the MSL test, it seems that this test represents a better correlation with subjects' eccentric strength, more than the isometric capacity.

Therefore, both MNR and MSL are closely related to strength parameters in elbow flexors and extensors. It has been previously claimed66 Silva BVC, Marocolo Junior M, Simim MAM, Franchini E, Mota GR. Performance in kimono grip strength tests among Brazilian Jiu Jitsu practitioners from different levels. J Comb Sports Mart Arts 2014;5(2):11-15. that the MNR test represents a more precise way to estimate strength parameters than handgrip dynamometers in JJ athletes. In the present study, even with the dynamic patterns of the test, MNR presented supposedly a higher index of correlations than MSL for every angle evaluated isometrically or dynamically, both for elbow flexors and extensors. These results suggest that MNR test could assess muscular strength parameters in JJ athletes, with high levels of correlation with isometric, concentric, and eccentric PT, measured by isokinetic dynamometry.

Generally, strong hands is a sign of health elsewhere, so handgrip strength is a good marker of overall muscle strength and a predictor of clinical severity in diseased and other elderly people [3] . It is readily available bedside test, easily performed, not affected by inflammation or the hydration state [4] . 041b061a72