Talent identification of 13 - 17 year old male and female cyclists in regional Queensland

The purpose of this study was to determine which performance test from Phase 1 of a cycling Talent Identification program (TID) discriminated the selection and non-selection of individuals with the potential to become high performance cyclists. 1058 school age individuals (males n=559, 14.0 ± 2 yr, 170.1 ± 11.0 cm, mass 62.0 ± 7.2 kg; females n= 499, 14.4 ± 1.5 yr, 164.0 ± 7.2 cm, mass 59.0 ± 14.2 kg) from the Rockhampton region participated in Phase 1 of a National Talent Search Program conducted by the Queensland Academy of Sport and the School of Health and Human Performance at Central Queensland University. The performance tests conducted were: arm span, seated basketball throw, vertical jump, 40m sprint and a 20m multistage endurance fitness test. An independent sample t-test (P<0.05) revealed that the vertical jump was significantly different between the selected and non-selected males (P<0.01) and females (P<0.05). Furthermore, in males, the 40m sprint and the multistage fitness endurance test was significantly different between the selected and non-selected athletes (P<0.00). In conclusion the results, of this study strongly suggest that both the vertical jump and multistage fitness test discriminate between selected and non-selected individuals in identifying prospective cycling talent

A comparison of fine wire insertion techniques for deep finger flexor muscle electromyography

Introduction: Intramuscular electromyography electrodes targeting flexor digitorum profundus (FDP) are inserted via the anterior or medial aspect of the forearm. These two methods pose different risks to neurovascular structures which overly FDP. This study aimed to compare the insertion depth and consider advantages and limitations of two different techniques to insert intramuscular electrodes into FDP. Methods: Using ultrasound imaging, neurovascular structures were identified along the path of FDP electrode insertion at the junction of the proximal and middle third of the ulna, bilaterally, in ten healthy individuals. Insertion depth was compared between the anterior and medial approaches for the mid muscle belly and targeted insertion to the index finger fascicle of FDP. Results: In our sample the ulnar artery was superficial to the FDP muscle when viewed anteriorly and was beyond the furthest border of FDP when viewed medially. Compared to the anterior approach, the medial insertion depth was 1.5 cm (95%CI 1.4–1.7, p < 0.001) less to the mid-belly of FDP and 0.6 cm (95%CI 0.4–0.7, p < 0.001) less to the index finger fascicle of FDP. Discussion: The medial approach involves less depth and lower risk for perforation of neurovascular structures when inserting intramuscular electrodes into the FDP muscle. © 2018 Elsevier Lt

Massage induces an immediate, albeit short-term, reduction in muscle stiffness

© 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.Using ultrasound shear wave elastography, the aims of this study were: (a) to evaluate the effect of massage on stiffness of the medial gastrocnemius (MG) muscle and (b) to determine whether this effect (if any) persists over a short period of rest. A 7-min massage protocol was performed unilaterally on MG in 18 healthy volunteers. Measurements of muscle shear elastic modulus (stiffness) were performed bilaterally (control and massaged leg) in a moderately stretched position at three time points: before massage (baseline), directly after massage (follow-up 1), and following 3min of rest (follow-up 2). Directly after massage, participants rated pain experienced during the massage. MG shear elastic modulus of the massaged leg decreased significantly at follow-up 1 (-5.2±8.8%, P=0.019, d=-0.66). There was no difference between follow-up 2 and baseline for the massaged leg (P=0.83) indicating that muscle stiffness returned to baseline values. Shear elastic modulus was not different between time points in the control leg. There was no association between perceived pain during the massage and stiffness reduction (r=0.035; P=0.89). This is the first study to provide evidence that massage reduces muscle stiffness. However, this effect is short lived and returns to baseline values quickly after cessation of the massage

Do insertional and mid-portion Achilles tendinopathy display different material properties?

We thank Zhang et al for their letter to the editor which raises the question as to whether insertional and non-insertional (or midportion) Achilles tendinopathy have different “stiffness patterns.” This proposal is based on findings of greater “hardness” in insertional Achilles tendinopathy in the study by Zhang et al,1 and lower “elastic modulus” in the study by Coombes et al,2 which recruited participants with a clinical diagnosis of Achilles tendinopathy at either region. While plausible, there are several critical differences between the two studies that ought to be considered

Achilles and patellar tendinopathy display opposite changes in elastic properties: A shear wave elastography study

To compare tendon elastic and structural properties of healthy individuals with those with Achilles or patellar tendinopathy. Sixty-seven participants (22 Achilles tendinopathy, 17 patellar tendinopathy, and 28 healthy controls) were recruited between March 2015 and March 2016. Shear wave velocity (SWV), an index of tissue elastic modulus, and tendon thickness were measured bilaterally at mid-tendon and insertional regions of Achilles and patellar tendons by an examiner blinded to group. Analysis of covariance, adjusted for age, body mass index, and sex was used to compare differences in tendon thickness and SWV between the two tendinopathy groups (relative to controls) and regions. Tendon thickness was included as a covariate for analysis of SWV. Compared to controls, participants with Achilles tendinopathy had lower SWV at the distal insertion (Mean difference MD; 95% CI: −1.56; −2.49 to −0.62 m/s; P <.001) and greater thickness at the mid-tendon (MD 0.19; 0.05-0.33 cm; P =.007). Compared to controls, participants with patellar tendinopathy had higher SWV at both regions (MD 1.25; 0.40-2.10 m/s; P =.005) and greater thickness proximally (MD 0.17; 0.06-0.29 cm; P =.003). Compared to controls, participants with Achilles and patellar tendinopathy displayed lower Achilles tendon elastic modulus and higher patellar tendon elastic modulus, respectively. More research is needed to explore whether maturation, aging, or chronic load underlie these findings and whether current management programs for Achilles and patellar tendinopathy need to be tailored to the tendon. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Lt

Response to considerations on “Achilles tendinopathy and patellar tendinopathy display opposite changes in elastic properties”

Letter to the edito

Shear-wave velocity of the patellar tendon and quadriceps muscle is increased immediately after maximal eccentric exercise

Purpose: To determine whether stiffness of the patellar tendon and quadriceps muscles is altered immediately after and 48 h after a single bout of maximal eccentric exercise of the knee extensor muscles. Methods: Thirteen healthy individuals [group mean (SD) age 22.4 (3.5) years; 7 female] performed a single bout of maximal eccentric exercise of the non-dominant knee extensors, using an isokinetic dynamometer. Shear-wave velocity (an index of tissue stiffness) was recorded from the patellar tendon, vastus medialis (VM), rectus femoris (RF) and vastus lateralis (VL), before, following (post0), and 48 h after (post48) exercise. To investigate features of exercise induced muscle damage, maximal voluntary isometric contraction (MVIC) and self-reported pain and stiffness (numerical rating scales 0 = no pain/stiffness to 100 = worst imaginable pain/stiffness) were measured before, post0, and post48 exercise. Serum creatine kinase (CK) was measured before and post48 exercise. Results: Compared to preexercise, MVIC decreased and self-reported pain and stiffness increased at post0 and post48 and CK levels increased at post48 (all p < 0.01). Compared to preexercise, shear-wave velocity was greater at post0 for the patellar tendon [15.9 (24.6)%, p = 0.01] and RF [23.6 (16.7)%, p < 0.001], each returning to baseline by post48. No significant differences were observed for VL or VM post0 or post48 exercise. Conclusion: Maximal eccentric exercise produced an immediate increase in the stiffness of the patellar tendon and RF, resolving by 48 h. As this change was not observed in VL and VM, future studies may explore heterogeneity within synergist muscles following eccentric exercise. © 2018, Springer-Verlag GmbH Germany, part of Springer Nature