scholarly journals The Relationship Between Speed and Strength in the Beach Volleyball Serve

2021 ◽  
Vol 80 (1) ◽  
pp. 39-47
Author(s):  
Mario Terol-Sanchis ◽  
Carlos Elvira-Aranda ◽  
María José Gomis-Gomis ◽  
José Antonio Pérez-Turpin

Abstract The objective of this study was to analyze the relationship between isometric force produced in different joints and its effects on the power kick serve speed in beach volleyball as a predictive aspect to improve sports performance. Seven athletes competing at national and international levels (mean ± standard deviation; age: 21.6 ± 3.20 years; body height: 1.87 ± 0.08 cm; body mass 80.18 ± 7.11 kg) were evaluated using maximum isometric force contractions (i.e., spinal and knee extension, grip by a hand dynamometer (handgrip), internal shoulder rotation, shoulder flexion, elbow flexion and extension, and wrist flexion). Speed of the ball was recorded with a pistol radar and force was measured with a strain gauge. Results showed a relationship between isometric force developed in the internal rotation of the shoulder and speed of the ball (r = 0.76*; p < 0.05). In the remaining isometric exercises, positive low to moderate correlations were found in the spine and knee extension (r = 0.56; p = 0.200) and elbow flexion (r = 0.41; p = 0.375). On the other hand, the remaining isometric exercises obtained weak or non-significant correlations. Force developed in the internal rotation of the shoulder highly correlated with the speed of the power kick, explaining, together with the elbow flexion and the extension of the knee and back, much of the variability of the power kick of beach volleyball athletes.

2016 ◽  
Vol 53 (1) ◽  
pp. 63-71 ◽  
Author(s):  
Ernest Baiget ◽  
Francisco Corbi ◽  
Juan Pedro Fuentes ◽  
Jaime Fernández-Fernández

AbstractThe aims of this study were to analyze the relationship between maximum isometric strength levels in different upper and lower limb joints and serve velocity in competitive tennis players as well as to develop a prediction model based on this information. Twelve male competitive tennis players (mean ± SD; age: 17.2 ± 1.0 years; body height: 180.1 ± 6.2 cm; body mass: 71.9 ± 5.6 kg) were tested using maximum isometric strength levels (i.e., wrist, elbow and shoulder flexion and extension; leg and back extension; shoulder external and internal rotation). Serve velocity was measured using a radar gun. Results showed a strong positive relationship between serve velocity and shoulder internal rotation (r = 0.67; p < 0.05). Low to moderate correlations were also found between serve velocity and wrist, elbow and shoulder flexion – extension, leg and back extension and shoulder external rotation (r = 0.36 – 0.53; p = 0.377 – 0.054). Bivariate and multivariate models for predicting serve velocity were developed, with shoulder flexion and internal rotation explaining 55% of the variance in serve velocity (r = 0.74; p < 0.001). The maximum isometric strength level in shoulder internal rotation was strongly related to serve velocity, and a large part of the variability in serve velocity was explained by the maximum isometric strength levels in shoulder internal rotation and shoulder flexion.


2015 ◽  
Vol 3 (1) ◽  
Author(s):  
Prisilia M. Pinontoan ◽  
Sylvia R. Marunduh ◽  
Herlina I. S. Wungouw

Abstract: The aim of this study was to find out the profile of muscle strength on elderly at BPLU Senja Cerah Paniki Bawah. This was a descriptive study with cross sectional design. There were 26 respondents who met the inclusion criteria, consisted of 10 elderly men and 16 elderly women. Respondents were selected by using purposive sampling method. The measurements of the muscle strength were done by using 1 RM method while doing elbow flexion, elbow extension, shoulder flexion, shoulder extension, shoulder abduction, knee flexion, knee extension and dorsoflexion. Data were analyzed manually and computerized then presented in tabular form. The result shows that the average muscle strength in elderly men were greater than women and the average muscle strength of respondents that were included in the age group 60-79 years old were greater than those in 80-99 years.Keywords: muscle strength, elderly.1 RMAbstrak: Tujuan dari penelitian ini yaitu untuk mengetahui gambaran kekuatan otot pada Lansia di BPLU Senja Cerah Paniki Bawah. Penelitian ini merupakan peneliltian deskriptif dengan rancangan potong lintang. Responden yang memenuhi kriteria inklusi terdiri dari 26 orang yang terdiri dari 10 orang laki-laki dan 16 orang perempuan. Sampel dipilih menggunakan cara purposive sampling. Kekuatan otot pada lansia diukur dengan menggunakan metode 1 RM yang diukur pada gerakan fleksi siku, ekstensi siku, fleksi bahu, ekstensi bahu, abduksi bahu, fleksi lutut, ekstensi lutut serta dorsofleksi. Data yang sudah didapatkan kemudian dikumpul dan diolah secara manual dan komputerisasi serta disajikan dalam bentuk tabel. Hasil penelitian menunjukkan rerata kekuatan otot responden laki-laki lebih besar dibanding perempuan dan rerata kekuatan responden yang termasuk dalam kelompok umur 60-79 tahun lebih besar dibanding kelompok umur 80-99 tahun.Kata kunci: kekuatan otot, lansia, 1 RM.


Author(s):  
Anne Schwarz ◽  
Miguel M. C. Bhagubai ◽  
Saskia H. G. Nies ◽  
Jeremia P. O. Held ◽  
Peter H. Veltink ◽  
...  

Abstract Background Upper limb kinematic assessments provide quantifiable information on qualitative movement behavior and limitations after stroke. A comprehensive characterization of spatiotemporal kinematics of stroke subjects during upper limb daily living activities is lacking. Herein, kinematic expressions were investigated with respect to different movement types and impairment levels for the entire task as well as for motion subphases. Method Chronic stroke subjects with upper limb movement impairments and healthy subjects performed a set of daily living activities including gesture and grasp movements. Kinematic measures of trunk displacement, shoulder flexion/extension, shoulder abduction/adduction, elbow flexion/extension, forearm pronation/supination, wrist flexion/extension, movement time, hand peak velocity, number of velocity peaks (NVP), and spectral arc length (SPARC) were extracted for the whole movement as well as the subphases of reaching distally and proximally. The effects of the factors gesture versus grasp movements, and the impairment level on the kinematics of the whole task were tested. Similarities considering the metrics expressions and relations were investigated for the subphases of reaching proximally and distally between tasks and subgroups. Results Data of 26 stroke and 5 healthy subjects were included. Gesture and grasp movements were differently expressed across subjects. Gestures were performed with larger shoulder motions besides higher peak velocity. Grasp movements were expressed by larger trunk, forearm, and wrist motions. Trunk displacement, movement time, and NVP increased and shoulder flexion/extension decreased significantly with increased impairment level. Across tasks, phases of reaching distally were comparable in terms of trunk displacement, shoulder motions and peak velocity, while reaching proximally showed comparable expressions in trunk motions. Consistent metric relations during reaching distally were found between shoulder flexion/extension, elbow flexion/extension, peak velocity, and between movement time, NVP, and SPARC. Reaching proximally revealed reproducible correlations between forearm pronation/supination and wrist flexion/extension, movement time and NVP. Conclusion Spatiotemporal differences between gestures versus grasp movements and between different impairment levels were confirmed. The consistencies of metric expressions during movement subphases across tasks can be useful for linking kinematic assessment standards and daily living measures in future research and performing task and study comparisons. Trial registration: ClinicalTrials.gov Identifier NCT03135093. Registered 26 April 2017, https://clinicaltrials.gov/ct2/show/NCT03135093.


Author(s):  
Dongjoon Kong ◽  
Andris Freivalds ◽  
Milind J. Kothari ◽  
Sanjiv H. Naidu

A group of 39 CTS patients with 60 affected hands participated in the study. A self-administered questionnaire developed by Levine et al. (1993) and nerve conduction measures (NCS) were used. The factor analysis showed a consistent result with previous studies: Primary (numbness, tingling, and nocturnal symptoms) and Secondary (pain, weakness, and clumsiness) symptoms. Peason's correlation coefficients showed that two primary symptoms (numbness and tingling) were highly correlated ( p <.05) with NCS results while the other symptoms were not. Among the primary symptoms, only nocturnal symptoms did not show any significant correlation with NCS results. The nocturnal symptoms could be more of a mechanical problem of wrist flexion at night and not a reflection of nerve slowing at night versus daytime but still was a good measure of CTS. The primary symptoms could be used as a potential screening tool for early CTS in the workplace.


2021 ◽  
Vol 77 (1) ◽  
pp. 15-24
Author(s):  
Klaus Mattes ◽  
Stefanie Wolff ◽  
Shahab Alizadeh

Abstract Maximum sprinting speed constitutes an optimum relation between the stride length and the step rate in addition to an appropriate sprinting technique. The kinematics of the sprint step at maximum sprinting speed have already been examined in numerous studies, without reaching a consensus. The aim of this study was to analyze the relationship between maximum sprinting speed and the stride kinematics based on the “Swing-Pull Technique”. German elite sprinters (N = 26, body height = 182 ± 6 cm, leg length 93.8 ± 4.1 cm) were tested while performing a 30-meter flying sprint at maximum sprinting speed. The relationship between sprinting speed and kinematic variables was determined via Pearson correlation. Sprinting speed (10.1 – 11.3 m/s) correlated with stride length (r = 0.53), ground contact time (r = -0.53) and variables from the technique model: the knee angle at the end of the knee lift swing (r = 0.40), the maximum knee angle prior to backswing (r = 0.40), the hip extension angle velocity (r = 0.63), and vertical foot velocity (r = 0.77) during pre-support, the ankle angle at the take-on (r = -0.43), knee flexion (r = -0.54), and knee extension (r = -0.47) during support. The results indicate that greater stride length, smaller contact time, and the mentioned kinematic step characteristics are relevant for the production of maximum sprinting speed in athletes at an intermediate to advanced performance level. The association of sprinting speed and these features should primarily be taken into account in conditioning and technical training.


2022 ◽  
pp. 036354652110678
Author(s):  
Joseph E. Manzi ◽  
Brittany Dowling ◽  
Zhaorui Wang ◽  
Andrew Luzzi ◽  
Ryan Thacher ◽  
...  

Background: Biomechanical predictors of pitching accuracy are underevaluated in baseball research. It is unclear how pitchers with higher accuracy differ in terms of kinematics and upper extremity kinetics. Purpose: To differentiate high- and low-accuracy professional pitchers by full-body kinematic and upper extremity kinetic parameters. Study Design: Descriptive laboratory study. Methods: In total, 121 professional baseball pitchers threw 8 to 12 fastballs while assessed with motion-capture technology (480 Hz). Pitchers were divided into high-accuracy (n = 33), moderate-accuracy (n = 52), and low-accuracy (n = 36) groups based on the absolute center deviation of each pitcher’s average pitch to the center of the pitching chart by greater or less than 0.5 SD from the mean, respectively. The 95% confidence ellipses with comparisons of major and minor radii and pitching probability density grids were constructed. Analysis of variance was used to compare kinematic and kinetic values between groups. Results: The absolute center deviation (14.5% ± 6.7% vs 33.5% ± 3.7% grid width; P < .001) was significantly lower in the high-accuracy compared with the low-accuracy group, with no significant difference in ball velocity (38.0 ± 1.7 vs 38.5 ± 2.0 m/s; P = .222). Lead knee flexion at ball release (30.6°± 17.8° vs 40.1°± 16.3°; P = .023) was significantly less for the high-accuracy pitchers. Peak normalized shoulder internal rotation torque (5.5% ± 1.0% vs 4.9% ± 0.7% body weight [BW] × body height [BH]; P = .008), normalized elbow varus torque (5.4% ± 1.0% vs 4.8% ± 0.7% BW × BH; P = .008), and normalized elbow medial force (42.9% ± 7.3% vs 38.6% ± 6.2% BW; P = .024) were significantly greater for the low-accuracy group compared with the high-accuracy group. Conclusion: Professional pitchers with increased accuracy experienced decreased throwing arm kinetics. These pitchers had increased lead knee extension at later stages of the pitch, potentially providing more stable engagement with the ground and transference of kinetic energy to the upper extremities. Professional pitchers can consider increasing lead knee extension at the final stages of the pitch to improve the accuracy of their throws and mitigate elbow varus torque. Clinical Relevance: Increased elbow varus torque, shoulder internal rotation torque, and elbow medial force in less accurate pitchers may contribute to increased injury risk in this group.


2018 ◽  
Vol 18 (02) ◽  
pp. 1850013 ◽  
Author(s):  
WEI WANG ◽  
DONGMEI WANG ◽  
CHENGHUI LAI

This study aimed to investigate three-dimensional (3D) kinematic characteristics of elbow and wrist motions, the relationship between them, and the anthropometric factors affecting them. Using motion capture system, this study measured and calculated the 3D angles of elbow flexion/extension, elbow pronation/supination, wrist flexion/extension, and wrist adduction/abduction of 40 healthy young adults. The study measured nine anthropometric variables and used unpaired [Formula: see text]-tests to assess gender difference. Also, bivariate correlation tests and step-wise multiple regression analyses were performed between joint ranges and anthropometric variables, as well as different joint motions. Results showed two opposite patterns occurred during elbow flexion/extension. The study found a correlation between the range of elbow flexion/extension and the range of elbow pronation/supination that occurred during elbow flexion/extension. Additionally, the study tested joint correlations between the four joint motions. Finally, the study established bivariate and multiple regression relationships between range of elbow motions and anthropometric factors. This research presented an unrecognized pattern of 3D elbow flexion/extension, and associations between various anthropometric factors and different joint motions. These findings can contribute to the design of orthosis of upper extremities and the rehabilitation of joint mobility.


Author(s):  
Michelle B. Kahn ◽  
Ross A. Clark ◽  
Gavin Williams ◽  
Kelly J. Bower ◽  
Megan Banky ◽  
...  

Abstract Background Upper limb associated reactions (ARs) are common in people with acquired brain injury (ABI). Despite this, there is no gold-standard outcome measure and no kinematic description of this movement disorder. The aim of this study was to determine the upper limb kinematic variables most frequently affected by ARs in people with ABI compared with a healthy cohort at matched walking speed intention. Methods A convenience sample of 36 healthy control adults (HCs) and 42 people with ABI who had upper limb ARs during walking were recruited and underwent assessment of their self-selected walking speed using the criterion-reference three dimensional motion analysis (3DMA) at Epworth Hospital, Melbourne. Shoulder flexion, abduction and rotation, elbow flexion, forearm rotation and wrist flexion were assessed. The mean angle, standard deviation (SD), peak joint angles and total joint angle range of motion (ROM) were calculated for each axis across the gait cycle. On a group level, ANCOVA was used to assess the between-group differences for each upper limb kinematic outcome variable. To quantify abnormality prevalence on an individual participant level, the percentage of ABI participants that were outside of the 95% confidence interval of the HC sample for each variable were calculated. Results There were significant between-group differences for all elbow and shoulder abduction outcome variables (p < 0.01), most shoulder flexion variables (except for shoulder extension peak), forearm rotation SD and ROM and for wrist flexion ROM. Elbow flexion and shoulder abduction were the axes most frequently affected by ARs. Despite the elbow being the most prevalently affected (38/42, 90%), a large proportion of participants had abnormality, defined as ±1.96 SD of the HC mean, present at the shoulder (32/42, 76%), forearm (20/42, 48%) and wrist joints (10/42, 24%). Conclusion This study provides valuable information on ARs, and highlights the need for clinical assessment of ARs to include all of the major joints of the upper limb. This may inform the development of a criterion-reference outcome measure or classification system specific to ARs.


1988 ◽  
Vol 40 (3) ◽  
pp. 545-560 ◽  
Author(s):  
Donald Siegel

The relationship between the rate of force development and components of fractionated reaction time were investigated in the present study. Subjects ( N=9) were administered extensive practice before being required to produce 98N of isometric force on a hand dynamometer at a maximal rate, at 20% slower than maximal, and at 40% slower than maximal. Repeated measures analysis of variance followed by non-orthogonal Dunn planned comparisons demonstrated that pre-motor time and reaction time increased as similar peak forces were produced over longer durations. No significant differences in motor times were revealed. These data suggested that the manner in which force is expressed relates to the complexity of motor programming. The increased requirement of coordinating alpha-gamma coactivation, as well as the increased need for rate coding as a process underlying force development at slower contraction rates, are discussed in relation to programming complexity.


2021 ◽  
pp. 1-7
Author(s):  
Camilla Sandberg ◽  
Albert G Crenshaw ◽  
Christina Christersson ◽  
Joanna Hlebowicz ◽  
Ulf Thilén ◽  
...  

Abstract Background: Patients with CHD exhibit reduced isometric muscle strength and muscle mass; however, little is known how these parameters relate. Therefore, the aim was to investigate the relation between isometric limb muscle strength and muscle mass for patients in comparison to age- and sex-matched control subjects. Methods: Seventy-four patients (35.6 ± 14.3 years, women n = 22) and 74 matched controls were included. Isometric muscle strength in elbow flexion, knee extension, and hand grip was assessed using dynamometers. Lean mass, reflecting skeletal muscle mass, in the arms and legs was assessed with dual-energy x-ray absorptiometry. Results: Compared to controls, patients had lower muscle strength in elbow flexion, knee extension, and hand grip, and lower muscle mass in the arms (6.6 ± 1.8 kg versus 5.8 ± 1.7 kg, p < 0.001) and legs (18.4 ± 3.5 kg versus 15.9 ± 3.2 kg, p < 0.001). There was no difference in achieved muscle force per unit muscle mass in patients compared to controls (elbow flexion 0.03 ± 0.004 versus 0.03 ± 0.005 N/g, p = 0.5; grip strength 0.008 ± 0.001 versus 0.008 ± 0.001 N/g, p = 0.7; knee extension 0.027 ± 0.06 versus 0.028 ± 0.06 N/g, p = 0.5). For both groups, muscle mass in the arms correlated strongly with muscle strength in elbow flexion (patients r = 0.86, controls, r = 0.89), hand grip (patients, r = 0.84, controls, r = 0.81), and muscle mass in the leg to knee extension (patients r = 0.64, controls r = 0.68). Conclusion: The relationship between isometric muscle strength and limb muscle mass in adults with CHD indicates that the skeletal muscles have the same efficiency as in healthy controls.


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