scholarly journals Elbow Extensors and Volar Flexors Strength Capacity and Its Relation to Shooting Performance in Basketball Players—A Pilot Study

2020 ◽  
Vol 10 (22) ◽  
pp. 8206
Author(s):  
Darjan Smajla ◽  
Žiga Kozinc ◽  
Nejc Šarabon
Keyword(s):  
Scaling Factor ◽  
Long Distance ◽  
Basketball Players ◽  
Rate Of Torque Development ◽  
Strength Capacity ◽  
Isometric Torque ◽  
Muscle Groups ◽  
Sufficient Strength ◽  
Torque Development ◽  
Basketball Shooting

Rate of force/torque development scaling factor (RFD-SF/RTD-SF) has been used as a tool for assessing neuromuscular quickness. The aim was to investigate strength capacities of two major shooting muscle groups and their relationship to basketball shooting performance, and to compare the RFD-SF as well as shooting performance between junior and senior basketball players, and finally to examine the differences in RTD-SF between elbow extensors and volar flexors. In 23 male basketball players (13 juniors and 10 seniors) we assessed maximal isometric torque (TMVC), maximal rate of torque development and RTD-SF slope (kRTD-SF) for elbow extensors and volar flexors. The subjects performed 10 throws at 2.3 m (short) and 8.9 m (long) from the basket. Our results showed similar kRTD-SF and TMVC in both groups. Better shooting performance from short distance was observed in senior players. Significant associations between kRTD-SF, TMVC and shooting performance were found only in juniors. Elbow extensors TMVC was found to have a significant positive large association with shooting performance from long distance. It seems that muscle capacity has an important role in shooting performance in junior compared to players. Sufficient strength capacity of major shooting muscles is important for juniors’ shooting performance from a long distance.

Hip Abductor Rate of Torque Development as Opposed to Isometric Strength Predicts Peak Knee Valgus During Landing: Implications for Anterior Cruciate Ligament Injury

2021 ◽  
pp. 1-6
Author(s):  
Kristen M. Stearns-Reider ◽  
Rachel K. Straub ◽  
Christopher M. Powers
Keyword(s):  
Cruciate Ligament ◽  
Muscle Performance ◽  
Ligament Injury ◽  
Knee Valgus ◽  
Rate Of Torque Development ◽  
Peak Knee ◽  
Hip Abductor ◽  
Isometric Torque ◽  
Anterior Cruciate ◽  
Torque Development

Peak knee valgus has been shown to predict anterior cruciate ligament injury. The purpose of the current study was to compare peak rate of torque development (RTD) to peak isometric torque as a predictor of peak knee valgus during landing. Twenty-three healthy females participated. Hip abductor muscle performance was quantified using 2 types of isometric contractions: sustained and rapid. Peak isometric torque was calculated from the sustained isometric contraction. Peak RTD was calculated from the rapid isometric contraction (0–50 and 0–200 ms after force initiation). Kinematic data were collected during the deceleration phase of a double-leg drop jump task. Linear regression was used to assess the ability of hip abductor muscle performance variables to predict peak knee valgus. Increased peak RTD during the 0 to 50 milliseconds window after force initiation was found to significantly predict lower peak knee valgus (P = .011, R2 = .32). In contrast, neither peak RTD from 0 to 200 milliseconds after force initiation window (P = .45, R2 = .03) nor peak isometric torque (P = .49, R2 = .03) predicted peak knee valgus. The inability of the hip abductors to rapidly generate muscular force may be more indicative of “at-risk” movement behavior in females than measures of maximum strength.

Peak power is reduced following lengthening contractions despite a maintenance of shortening velocity

2013 ◽  
Vol 38 (12) ◽  
pp. 1196-1205 ◽  
Author(s):  
Geoffrey A. Power ◽  
Brian H. Dalton ◽  
Charles L. Rice ◽  
Anthony A. Vandervoort
Keyword(s):  
Peak Power ◽  
Recovery Period ◽  
Shortening Velocity ◽  
Lengthening Contractions ◽  
Maximum Voluntary Isometric Contraction ◽  
Relative Contribution ◽  
Rate Of Torque Development ◽  
Isometric Torque ◽  
Torque Development ◽  
Shortening Contractions

Following repetitive lengthening contractions, power (the product of torque and velocity) is impaired during shortening contractions. However, the relative contribution of each component to power loss and the underlying factors are unclear. We investigated neuromuscular properties of the dorsiflexors in 8 males (27 ± 3 years) and 8 females (26 ± 4 years) for a potential sex-related difference before, during, and after 150 unaccustomed maximal lengthening actions. Velocity-dependent power was determined from shortening contractions at 8 levels (1 N·m to 70% of maximum voluntary isometric contraction (MVC)) before, after, and throughout recovery assessed at 0–30 min, 24 h, and 48 h. Immediately following task termination, both sexes displayed similar impairments of 30%, 4%, and 10% in MVC torque, shortening velocity, and overall peak power, respectively (P < 0.05). Peak rate of isometric torque development (RTD) was reduced by 10% in males, but females exhibited a 35% reduction (P < 0.05). Rate of torque development for the MVC remained depressed in both sexes throughout the 30 min recovery period; however, the RTD returned to normal by 24 h in males but did not recover by 48 h in females. Power was reduced preferentially at higher loads (i.e., 60% MVC), with a greater loss in females (65%) than males (45%). For lower loads (<20% MVC), power was impaired minimally (4%–8%; P < 0.05) and recovered within 30 min in both groups. The reduction in maximal angular velocity persisted until 30 min of recovery, and peak power did not recover until 24 h for both sexes. Unaccustomed lengthening contractions decreased power preferentially at higher loads, whereas peak power was reduced minimally owing to maintenance of maximal shortening velocity.

scholarly journals Plyometric Exercises from a Knee Anterior Cruciate Ligament Prevention Program on the Rate of Isometric Torque Development and Vertical Jump Height

2018 ◽  
Author(s):  
Jeffrey Doeringer ◽  
Sam Johnson ◽  
Marc Norcorss ◽  
Mark Hoffman
Keyword(s):  
Anterior Cruciate Ligament ◽  
Injury Prevention ◽  
Prevention Program ◽  
Cruciate Ligament ◽  
Vertical Jump ◽  
Plyometric Training ◽  
Rate Of Torque Development ◽  
Isometric Torque ◽  
Anterior Cruciate ◽  
Torque Development

Purpose: Plyometric exercises are incorporated in anterior cruciate ligament injures of the knee (ACL) injury prevention programs that have effectively decreased risk factors for anterior cruciate ligament injures of the knee injuries, but the impact on the rate of isometric torque development of the musculature of the knee is unclear. The purpose of this study was to determine the effects of a 6-week plyometric program pulled from a commonly utilized anterior cruciate ligament injures of the knee injury prevention program on rate of isometric torque development (RTD) in healthy active females. Methods: College-aged participants were randomly split into two different groups (16-plyometric training and 15-control). Plyometric exercises included 180° jumps, bounding for distance, bounding in place, broad jump-stick, cone jumps, hop - hop stick, jump into bounding, jump - jump - jump vertical jump, mattress jumps, scissors jump, single-legged jumps for distance, squat jumps, step-jump up-down-vertical jump, tuck jumps, and wall jumps. Participants in the training group performed the exercises three times a week on alternating days, for 30-minute sessions. All participants performed a vertical jump measurement and completed maximum voluntary isometric contractions (MVICs) of ankle plantar flexion, knee extension, and knee flexion rate of torque development. Results: There was a main effect of session for plantar flexion rate of torque development time windows and vertical jump. The analysis revealed no significant differences for group by session interactions for any other rate of torque development measurement or the vertical jump. Conclusions: Plyometric exercises utilized from an anterior cruciate ligament injures of the knee injury prevention program did not change lower body isometric torque development or vertical jump height of active females. Since the plyometric training did not improve vertical jump, the training may not have been performed vigorous enough for the participants to cause a neuromuscular adaptation. Based on findings, 6-weeks of plyometric training from an isolated ACL injury prevention program should not be used to increase the vertical jump of healthy, active females.

Postactivation potentiation in a human muscle: effect on the rate of torque development of tetanic and voluntary isometric contractions

2007 ◽  
Vol 102 (4) ◽  
pp. 1394-1401 ◽  
Author(s):  
Stéphane Baudry ◽  
Jacques Duchateau
Keyword(s):  
Muscle Activation ◽  
Muscle Performance ◽  
Similar Degree ◽  
Postactivation Potentiation ◽  
Muscle Twitch ◽  
Rate Of Torque Development ◽  
Adductor Muscles ◽  
Isometric Torque ◽  
Voluntary Contractions ◽  
Torque Development

Postactivation potentiation (PAP), a mechanism by which the torque of a muscle twitch is increased following a conditioning contraction, is well documented in muscular physiology, but little is known about its effect on the maximal rate of torque development and functional significance during voluntary movements. The objective of this study was to investigate the PAP effect on the rate of isometric torque development of electrically induced and voluntary contractions. To that purpose, the electromechanical responses of the thumb adductor muscles to a single electrical stimulus (twitch), a train of 15 pulses at 250 Hz (HFT250), and during ballistic (i.e., rapid torque development) voluntary contractions at torque levels ranging from 10 to 75% of maximal voluntary contraction (MVC) were recorded before and after a conditioning 6-s MVC. The results showed that the rate of torque development was significantly ( P < 0.001) increased after the conditioning MVC, but the effect was greater for the twitch (∼200%) compared with the HFT250 (∼17%) or ballistic contractions (range: 9–24%). Although twitch potentiation was maximal immediately after the conditioning MVC, maximal potentiation for HFT250 and ballistic contractions was delayed to 1 min after the 6-s MVC. Furthermore, the similar degree of potentiation for the rate of isometric torque development between tetanic and voluntary ballistic contractions indicates that PAP is not related to the modality of muscle activation. These observations suggest that PAP may be considered as a mechanism that can influence our contractions during daily tasks and can be utilized to improve muscle performance in explosive sports.

scholarly journals Change of Direction Performance Is Influenced by Asymmetries in Jumping Ability and Hip and Trunk Strength in Elite Basketball Players

2020 ◽  
Vol 10 (19) ◽  
pp. 6984
Author(s):  
Filip Ujaković ◽  
Nejc Šarabon
Keyword(s):  
Regression Model ◽  
Range Of Motion ◽  
Sport Performance ◽  
Leg Length ◽  
Basketball Players ◽  
Change Of Direction ◽  
Rate Of Torque Development ◽  
Hip Flexion ◽  
Torque Development ◽  
Trunk Strength

Change of direction (COD) ability is essential for sport performance in high level team sports such as basketball, however, the influence of asymmetries on COD ability is relatively unknown. Forty-three junior and senior level elite basketball players performed isometric hip and trunk strength testing, passive hip and trunk range of motion testing, and unilateral horizontal and vertical jumps, as well as the T-test to measure COD performance. Mean asymmetry values ranged from 0.76% for functional leg length up to 40.35% for rate of torque development during hip flexion. A six-variable regression model explained 48% (R2 = 0.48; p < 0.001) of variation in COD performance. The model included left hip internal/external rotation strength ratio, and inter-limb asymmetries in hip abduction rate of torque development, hip flexion range of motion, functional leg length, single leg triple jump distance, and peak torque during trunk lateral flexion. Results suggest that the magnitude of asymmetries is dependent of task and parameter, and using universal asymmetry thresholds, such as <10 %, is not optimal. The regression model showed the relationship between asymmetries and COD performance. None of tests were sufficient to explain a complex variable like COD performance.

scholarly journals Interlimb Asymmetries and Ipsilateral Associations of Plantar Flexors and Knee Extensors Rate-of-Force Development Scaling Factor

Symmetry ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 1522
Author(s):  
Darjan Smajla ◽  
Olivera M. Knezevic ◽  
Dragan M. Mirkov ◽  
Nejc Šarabon
Keyword(s):  
Regression Line ◽  
Force Production ◽  
Scaling Factor ◽  
Lower Limbs ◽  
Knee Extensors ◽  
Future Research ◽  
Isometric Contractions ◽  
Plantar Flexors ◽  
Muscle Groups ◽  
Torque Development

Rate of force/torque development scaling factor (RFD-SF/RTD-SF) was recently introduced as a tool to quantify the neuromuscular quickness, and it could have potential for interlimb asymmetry identification. Moreover, positive relationships in RFD-SF ability among different muscle groups were shown, but not in the lower extremity. The first aim of our study was to use RTD-SF for interlimb asymmetry identification. The second aim was to determine associations between plantar flexors (PF) and knee extensors (KE). Forty young healthy athletes (14.8 ± 1.2 years) performed explosive isometric contractions to a span of torque levels for PF and KE. From rapid isometric contractions, the RTD-SF and linearity (r2) of the regression line were calculated. Using RTD-SF we identified 10% (PF) and 15% (KE) of subjects with contralateral asymmetries (>15% criterion). The results revealed significant positive moderate correlation in RTD-SF between PF and KE (r = 0.401, p < 0.05). We supported that RTD-SF can be a useful tool for interlimb asymmetry identification. Future research about observed asymmetry in rapid submaximal contractions deserves more attention, as most of the functional sport specific activities put high demands on rapid force production. Our study as first confirmed positive associations in RTD-SF ability between muscle groups in lower limbs.

Knee flexor strength, rate of torque development and flexibility in women and men with patellofemoral pain: Relationship with pain and the single leg bridge test

2021 ◽  
Author(s):  
Matheus Henrique Maiolini Ducatti ◽  
Marina Cabral Waiteman ◽  
Ana Flávia Balotari Botta ◽  
Helder dos Santos Lopes ◽  
Neal Robert Glaviano ◽  
...  
Keyword(s):  
Patellofemoral Pain ◽  
Knee Flexor ◽  
Rate Of Torque Development ◽  
Torque Development ◽  
Flexor Strength

scholarly journals Locomotor Anatomy and Behavior of Patas Monkeys (Erythrocebus patas) with Comparison to Vervet Monkeys (Cercopithecus aethiops)

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Adrienne L. Zihlman ◽  
Carol E. Underwood
Keyword(s):  
Cercopithecus Aethiops ◽  
Whole Body ◽  
Relative Mass ◽  
Vervet Monkeys ◽  
Long Distance ◽  
Erythrocebus Patas ◽  
Locomotor System ◽  
Patas Monkeys ◽  
Foot Bones ◽  
Muscle Groups

Patas monkeys (Erythrocebus patas) living in African savanna woodlands and grassland habitats have a locomotor system that allows them to run fast, presumably to avoid predators. Long fore- and hindlimbs, long foot bones, short toes, and a digitigrade foot posture were proposed as anatomical correlates with speed. In addition to skeletal proportions, soft tissue and whole body proportions are important components of the locomotor system. To further distinguish patas anatomy from other Old World monkeys, a comparative study based on dissection of skin, muscle, and bone from complete individuals of patas and vervet monkeys (Cercopithecus aethiops) was undertaken. Analysis reveals that small adjustments in patas skeletal proportions, relative mass of limbs and tail, and specific muscle groups promote efficient sagittal limb motion. The ability to run fast is based on a locomotor system adapted for long distance walking. The patas’ larger home range and longer daily range than those of vervets give them access to highly dispersed, nutritious foods, water, and sleeping trees. Furthermore, patas monkeys have physiological adaptations that enable them to tolerate and dissipate heat. These features all contribute to the distinct adaptation that is the patas monkeys’ basis for survival in grassland and savanna woodland areas.

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