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Keith Baar

due to the high playing load and intensity. In a preliminary report from the Australian National Basketball League, 52.3% of players reported patellar tendon pain that limited performance ( Hannington et al., 2017 ), suggesting that the prevalence of this injury is high at the elite level. Typically

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Christopher Tack, Faye Shorthouse and Lindsy Kass

[“what is the effect of dietary supplements on musculoskeletal tissue (e.g., cartilage, tendon, muscle, ligament) healing compared to placebo or other control?”] and was used to formulate a search of Google Scholar and PubMed to evaluate the quality/volume of the existing literature. This search produced

Open access

Alireza Esmaeili, Andrew M. Stewart, William G. Hopkins, George P. Elias and Robert J. Aughey

Purpose:

Detrimental changes in tendon structure increase the risk of tendinopathies. The aim of this study was to investigate the influence of individual internal and external training loads and leg dominance on changes in the Achilles and patellar tendon structure.

Methods:

The internal structure of the Achilles and patellar tendons of both limbs of 26 elite Australian footballers was assessed using ultrasound tissue characterization at the beginning and the end of an 18-wk preseason. Linear-regression analysis was used to estimate the effects of training load on changes in the proportion of aligned and intact tendon bundles for each side. Standardization and magnitude-based inferences were used to interpret the findings.

Results:

Possibly to very likely small increases in the proportion of aligned and intact tendon bundles occurred in the dominant Achilles (initial value 81.1%; change, ±90% confidence limits 1.6%, ±1.0%), nondominant Achilles (80.8%; 0.9%, ±1.0%), dominant patellar (75.8%; 1.5%, ±1.5%), and nondominant patellar (76.8%; 2.7%, ±1.4%) tendons. Measures of training load had inconsistent effects on changes in tendon structure; eg, there were possibly to likely small positive effects on the structure of the nondominant Achilles tendon, likely small negative effects on the dominant Achilles tendon, and predominantly no clear effects on the patellar tendons.

Conclusion:

The small and inconsistent effects of training load are indicative of the role of recovery between tendon-overloading (training) sessions and the multivariate nature of the tendon response to load, with leg dominance a possible influencing factor.

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Rebekah D. Alcock, Gregory C. Shaw, Nicolin Tee, Marijke Welvaert and Louise M. Burke

), serves as a key tensile element within connective and structural tissues such as muscles, ligaments, tendons, and bone, due to cross-linking within its triple-helical structure ( Kadler et al., 2007 ). Although in its infancy, developing research suggests that it may be possible to nutritionally support

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Rebekah D. Alcock, Gregory C. Shaw and Louise M. Burke

; Zdzieblik et al., 2015 ) and athletic populations (e.g., for the prevention and management of connective tissue injury; Baar, 2015 , 2017 ). Although whey protein has been shown to enhance patella tendon hypertrophy in young males when combined with a 12-week resistance exercise training program ( Farup

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Harriet G. Williams and Jeanmarie R. Burke

A conditioned patellar tendon reflex paradigm was used to study the contributions of crossed spinal and supraspinal inputs to the output of the alpha motoneuron pool in children with and without developmental coordination disorders. The basic patellar tendon reflex response was exaggerated in children with developmental coordination disorders. Crossed spinal and supraspinal influences on the excitability of the alpha motoneuron pool were similar in both groups of children. However, there was evidence of exaggerated crossed spinal and supraspinal inputs onto the alpha motoneuron pool in individual children with developmental coordination disorder.

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Erik Schrödter, Gert-Peter Brüggemann and Steffen Willwacher

Purpose:

To describe the stretch-shortening behavior of ankle plantar-flexing muscle–tendon units (MTUs) during the push-off in a sprint start.

Methods:

Fifty-four male (100-m personal best: 9.58–12.07 s) and 34 female (100-m personal best: 11.05–14.00 s) sprinters were analyzed using an instrumented starting block and 2-dimensional high-speed video imaging. Analysis was performed separately for front and rear legs, while accounting for block obliquities and performance levels.

Results:

The results showed clear signs of a dorsiflexion in the upper ankle joint (front block 15.8° ± 7.4°, 95% CI 13.2–18.2°; rear block 8.0° ± 5.7°, 95% CI 6.4–9.7°) preceding plantar flexion. When observed in their natural block settings, the athletes’ block obliquity did not significantly affect push-off characteristics. It seems that the stretch-shortening-cycle-like motion of the soleus MTU has an enhancing influence on push-off force generation.

Conclusion:

This study provides the first systematic observation of ankle-joint stretch-shortening behavior for sprinters of a wide range of performance levels. The findings highlight the importance of reactive-type training for the improvement of starting performance. Nonetheless, future studies need to resolve the independent contributions of tendinous and muscle-fascicle structures to overall MTU performance.

Open access

Graeme L. Close, Craig Sale, Keith Baar and Stephane Bermon

injuries, that is, skeletal muscle, bone, tendon, and ligament. We include a review of the extant literature that has looked at nutrition to prevent injuries and increase repair, as well as considering the change in energy requirements during the injury period. Nutrition to Prevent and Treat Muscle

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Simon A. Rogers, Chris S. Whatman, Simon N. Pearson and Andrew E. Kilding

stiffness (vertical, leg, and joint) incorporating a greater number of musculoskeletal and neural components involved in jumping and running tasks. 17 Global stiffness is informed by isolated or component measures in the lower limbs, which examine various muscle-tendon units (MTUs) in an effort to

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Fábio J. Lanferdini, Rodrigo R. Bini, Pedro Figueiredo, Fernando Diefenthaeler, Carlos B. Mota, Anton Arndt and Marco A. Vaz

Purpose:

To employ cluster analysis to assess if cyclists would opt for different strategies in terms of neuromuscular patterns when pedaling at the power output of their second ventilatory threshold (POVT2) compared with cycling at their maximal power output (POMAX).

Methods:

Twenty athletes performed an incremental cycling test to determine their power output (POMAX and POVT2; first session), and pedal forces, muscle activation, muscle–tendon unit length, and vastus lateralis architecture (fascicle length, pennation angle, and muscle thickness) were recorded (second session) in POMAX and POVT2. Athletes were assigned to 2 clusters based on the behavior of outcome variables at POVT2 and POMAX using cluster analysis.

Results:

Clusters 1 (n = 14) and 2 (n = 6) showed similar power output and oxygen uptake. Cluster 1 presented larger increases in pedal force and knee power than cluster 2, without differences for the index of effectiveness. Cluster 1 presented less variation in knee angle, muscle–tendon unit length, pennation angle, and tendon length than cluster 2. However, clusters 1 and 2 showed similar muscle thickness, fascicle length, and muscle activation. When cycling at POVT2 vs POMAX, cyclists could opt for keeping a constant knee power and pedal-force production, associated with an increase in tendon excursion and a constant fascicle length.

Conclusions:

Increases in power output lead to greater variations in knee angle, muscle–tendon unit length, tendon length, and pennation angle of vastus lateralis for a similar knee-extensor activation and smaller pedal-force changes in cyclists from cluster 2 than in cluster 1.