In vivo assessment of elbow flexor work and activation during stretch-shortening cycle tasks

Benoît, Daniel; Dowling, James J.

doi:10.1016/j.jelekin.2004.07.006

Cited by 11 publications

(7 citation statements)

References 35 publications

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“…3. This stretch‐shortening action has been associated previously with a storage of elastic energy (Jacobs et al, 1996) and a significant increase in muscle work output (Benoit and Dowling, 2005). While it is clear from our investigation that the hamstring, rectus femoris and gastrocnemius muscles will undergo a stretch‐shortening cycle during both the WFL and JFL, examining how the performance enhancement of the stretch‐shortening cycle may contribute during the forward lunge is beyond the scope of this investigation.…”

Section: Discussionmentioning

confidence: 72%

Muscle activation and length changes during two lunge exercises: implications for rehabilitation

Jönhagen

Halvorsen

Benoît

2009

Scandinavian Med Sci Sports

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Eccentric exercises are commonly used as a treatment for various muscle and tendon injuries. During complex motions such as the forward lunge, however, it is not always clear which muscles may be contracting eccentrically and at what time. Because this exercise is used during rehabilitation, the purpose of this investigation was to determine what type of contractions take place during two different types of forward lunge and assess the implications for rehabilitation. Five experienced athletes performed five cycles for each of the walking and jumping forward lunges. Motion analysis was used to calculate the shortening or elongation of each muscle based on the change of position of their origin and insertion points during the lunge. Electromyography of the lateral hamstrings, rectus femoris and lateral gastrocnemius was combined with the muscle length change data to determine when isometric, concentric and eccentric activations occur during the lunge. Eccentric contractions in both the quadriceps and gastrocnemius were observed during the lunge. No hamstring eccentric contractions were found; however, the hamstrings showed isometric contractions during the first part of the stance phase.

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Section: Discussionmentioning

confidence: 72%

Muscle activation and length changes during two lunge exercises: implications for rehabilitation

Jönhagen

Halvorsen

Benoît

2009

Scandinavian Med Sci Sports

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“…Although stretch–shortening cycle includes an eccentric element, contrary to the type of maximal eccentric contractions typically used in exercise-induced muscle damage studies, the force and the eccentric phase involved in the active braking phase of stretch–shortening cycles are generally fast and of short duration (Nicol et al 2006 ). Interestingly, muscle activation decreases with increasing velocity in the eccentric phase under the stretch–shortening cycle conditions (Benoit and Dowling 2006 ), which indicates that other non-contractile (elastic) structures, such as the extracellular matrix/tendon, might provide important contribution to the power output by storing energy (Kjær 2004 ; Yang and Xu 2012 ). Indeed, a highly compliant elastic musculotendinous system is thought to elevate the use of elastic strain energy in stretch–shortening cycle movements (Wilson et al 1991 ).…”

Section: Genetic Variation and The Initial Phase Of Exercise-induced mentioning

confidence: 99%

Genetic variation and exercise-induced muscle damage: implications for athletic performance, injury and ageing

et al. 2016

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Prolonged unaccustomed exercise involving muscle lengthening (eccentric) actions can result in ultrastructural muscle disruption, impaired excitation–contraction coupling, inflammation and muscle protein degradation. This process is associated with delayed onset muscle soreness and is referred to as exercise-induced muscle damage. Although a certain amount of muscle damage may be necessary for adaptation to occur, excessive damage or inadequate recovery from exercise-induced muscle damage can increase injury risk, particularly in older individuals, who experience more damage and require longer to recover from muscle damaging exercise than younger adults. Furthermore, it is apparent that inter-individual variation exists in the response to exercise-induced muscle damage, and there is evidence that genetic variability may play a key role. Although this area of research is in its infancy, certain gene variations, or polymorphisms have been associated with exercise-induced muscle damage (i.e. individuals with certain genotypes experience greater muscle damage, and require longer recovery, following strenuous exercise). These polymorphisms include ACTN3 (R577X, rs1815739), TNF (−308 G>A, rs1800629), IL6 (−174 G>C, rs1800795), and IGF2 (ApaI, 17200 G>A, rs680). Knowing how someone is likely to respond to a particular type of exercise could help coaches/practitioners individualise the exercise training of their athletes/patients, thus maximising recovery and adaptation, while reducing overload-associated injury risk. The purpose of this review is to provide a critical analysis of the literature concerning gene polymorphisms associated with exercise-induced muscle damage, both in young and older individuals, and to highlight the potential mechanisms underpinning these associations, thus providing a better understanding of exercise-induced muscle damage.

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“…It has been widely used for evaluation of muscle function in the areas of biomechanics and kinesiology [1][2], muscle pathology [3], muscle fatigue [4], and prosthetic device control [5]. The root mean square (rms) magnitude and median frequency are commonly used to describe the time-domain and frequency-domain information of the EMG signal, respectively [6].…”

Section: Introductionmentioning

confidence: 99%

Dynamic monitoring of forearm muscles using one-dimensional sonomyography system

Guo

Zheng

Huang

et al. 2008

JRRD

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Abstract-We introduce a method, known as one-dimensional sonomyography (1-D SMG), that uses A-mode ultrasound signals to detect dynamic thickness changes in skeletal muscle during contraction. We custom-designed a 1-D SMG system to collect synchronized A-mode ultrasound, joint angle, and surface electromyography (EMG) signals of forearm muscles during wrist extension. We extracted the 1-D SMG signal from the ultrasound signal by automatically tracking the corresponding echoes, which we then used to calculate muscle thickness changes. We tested the right forearm muscles of nine nondisabled young subjects while they performed wrist extensions at 15.0, 22.5, and 30.0 cycles/min and their largest wrist extension angle ranged from 80° to 90°. We found that the muscle deformation and EMG root mean square signals correlated linearly with wrist extension angle. The ratio of deformation to wrist angle was significantly different among the subjects (p < 0.001) but not among the trials of different extension rates for each subject (p = 0.9). The results demonstrate that 1-D SMG can be reliably performed and that it has the potential for skeletal muscle assessment and prosthesis control.

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In vivo assessment of elbow flexor work and activation during stretch-shortening cycle tasks

Cited by 11 publications

References 35 publications

Muscle activation and length changes during two lunge exercises: implications for rehabilitation

Muscle activation and length changes during two lunge exercises: implications for rehabilitation

Genetic variation and exercise-induced muscle damage: implications for athletic performance, injury and ageing

Dynamic monitoring of forearm muscles using one-dimensional sonomyography system

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