Load management in tendinopathy: Clinical progression for Achilles and patellar tendinopathy / Gestión de la carga en las tendinopatías: progresión clínica para tendinopatías de Aquiles y rotuliana

Achilles and patellar tendons are commonly affected by tendinopathy. Injury to these tendons can severely impact upon sports, recreational and everyday activities. Eccentric musculotendinous loading has become the dominant conservative intervention strategy for Achilles and patellar tendinopathy over the last two decades. Eccentric loading involves isolated, slow lengthening muscle contractions. Systematic reviews have evaluated the evidence for eccentric muscle loading in Achilles and patellar tendinopathy, concluding that outcomes are promising but high-quality evidence is lacking. Eccentric loading may not be effective for all patients (athletes and non-athletes) affected by tendinopathy. It is possible that in athletes, eccentric work is an inadequate load on the muscle and tendon. A rehabilitation program aiming to increase tendon load tolerance must obviously include strength exercises, but should also add speed and energy storage and release. The aim of this paper is to document a rehabilitation protocol for Achilles and patellar tendinopathy. It consists of simple and pragmatic exercises designed to incorporate progressive load to the tendon: isometric work, strength, functional strength, speed and jumping exercises to adapt the tendon to the ability to store and release energy. This article would be the first step for an upcoming multicentre randomized controlled trial to investigate its efficacy (AU)

Las tendinopatías de Aquiles y rotuliana son muy frecuentes. Las lesiones en estos tendones pueden afectar severamente a las actividades deportivas, recreativas y cotidianas. En las últimas 2 décadas, los ejercicios excéntricos se han convertido en la principal intervención conservadora para tratar las tendinopatías de Aquiles y rotuliana. Los ejercicios excéntricos no son efectivos en todos los pacientes afectados por tendinopatías (atletas y no atletas). Es posible que en atletas, la carga que genera el trabajo excéntrico sobre el músculo y el tendón sea insuficiente. Un programa de rehabilitación que tenga por objetivo aumentar la tolerancia del tendón a la carga debe, obviamente, incluir ejercicios de fuerza, pero también debe agregar ejercicios de velocidad y ejercicios que aumenten la capacidad para almacenar y liberar energía. Este trabajo muestra un protocolo de rehabilitación para las tendinopatías de Aquiles y rotuliana. Consiste en ejercicios simples y pragmáticos diseñados para incorporar carga progresiva al tendón: mediante trabajo isométrico, fuerza, fuerza funcional, velocidad y ejercicios pliométricos que aumenten en el tendón la capacidad de almacenar y liberar energía. Este trabajo es el primer paso para diseñar un ensayo clínico aleatorizado y multicéntrico que permita evaluar su eficacia (AU)

Effect of the starting and turning performances on the subsequent swimming parameters of elite swimmers.

In the present research, we examined the effect of the starting and turning performances on the subsequent swimming parameters by (1) comparing the starting and turning velocities with the swimming parameters on the emersion and mid-pool segments and (2) by relating the individual behaviour of swimmers during the start and turns with subsequent behaviour on each swimming lap. One hundred and twelve 100 m performances on the FINA 2013 World Swimming Championships were analysed by an image-processing system (InThePool 2.0®). At the point of the start emersion, the swimming parameters of the 100-m elite swimmers were substantially greater than the mid-pool parameters, except on the breaststroke races. On the other hand, no diminution in the swimming parameters was observed between the turn emersion and the mid-pool swimming, except on the butterfly and backstroke male races. Changes on the surface swimming kinematics were not generally related to the starting or turning parameters, although male swimmers who develop faster starts seem to achieve faster velocities at emersion. Race analysts should be aware of a transfer of momentum when swimmers emerge from underwater with implications on the subsequent swimming kinematics, especially for male swimmers who employ underwater undulatory techniques.

Do faster swimmers spend longer underwater than slower swimmers at World Championships?

The main objectives of the present research were (1) to examine the relationships between the distances travelled underwater during the start and turn segments with swimming race performance at the elite level and (2) to determine if the individualised-distance start and turn parameters affect the overall race performance. The race parameters of the 100 and 200 m events during 2013 World Championships were measured by an innovative image-processing system (InThePool(®) 2.0). Overall, 100 m race times were largely related to faster start velocities in men's breaststroke and freestyle events. Conversely, overall, 200 m race times were largely related to longer starting distances in the women's butterfly events, to longer turn distances in men's and women's backstroke and women's butterfly events and to shorter turn distances in women's freestyle events. Changes on the start or turn velocities could represent moderate time improvements in most of the 100 m events, whereas modifications on the start or turn distances (especially in the last turn) could provide elite swimmers with time improvements of practical importance on the 200 m events. The evaluation of races by individualised-distance parameters should be provided to elite swimmers in order to decide the most appropriate race segment configuration for each event.

Underwater and surface strategies of 200 m world level swimmers.

Pacing strategies of elite swimmers have been consistently characterised from the average lap velocities. In the present study, we examined the racing strategies of 200 m world class-level swimmers with regard to their underwater and surface lap components. The finals and semi-finals of the 200 m races at the 2013 World Swimming Championships (Barcelona, Spain) were analysed by an innovative image-processing system (InThePool® 2.0). Free swimming velocities of elite swimmers typically decreased throughout the 200 m race laps (-0.12 m · s(-1), 95% CI -0.11 to -0.14 m · s(-1), P = 0.001, η(2) = 0.81), whereas underwater velocities, which were faster than free swimming, were not meaningfully affected by the race progress (0.02 m · s(-1), -0.01 to 0.04 m · s(-1), P = 0.01, η(2) = 0.04). When swimming underwater, elite swimmers typically travelled less distance (-0.66 m, -0.83 to -0.49 m, P = 0.001, η(2) = 0.34) from the first to the third turn of the race, although underwater distances were maintained on the backstroke and butterfly races. These strategies allowed swimmers to maintain their average velocity in the last lap despite a decrease in the free swimming velocity. Elite coaches and swimmers are advised to model their racing strategies by considering both underwater and surface race components.

Acute effects of small changes in bicycle saddle height on gross efficiency and lower limb kinematics.

The aim of the present study was to assess the acute effects of small changes in bicycle saddle height on gross efficiency (GE) and lower-limb kinematics. Well-trained cyclists (n = 14) performed a submaximal pedaling test (~70-75% of the v[Combining Dot Above]O2max) at constant cadence (90 rpm). It consisted of 3 randomized sets of 6 minutes with the preferred saddle height, 2% higher and 2% lower. Gross efficiency was significantly lower and oxygen consumption (v[Combining Dot Above]O2) was significantly higher when raising the saddle (GE = 19.9 ± 1.5%; V[Combining Dot Above]O2max = 43.8 ml·kg·min) than when lowering it (GE = 20.4 ± 1.3%; V[Combining Dot Above]O2 = 42.8 ml·kg·min). Additionally, a change of 0.8% in GE (20.6 ± 1.6% to 19.8 ± 1.6%, p < 0.05) was observed when comparing the positions where the best and worst GE was obtained. A significant effect of the small changes in saddle height on lower limb kinematics was also observed (p < 0.05). The differences between lower and higher saddle positions, in hip, knee, and ankle joints were an increase of extension (~4, 7, and 8°, respectively), a decrease of flexion (~3, 4, and 4°, respectively) and, consequently, an increase of the range of movement (~1, 3, and 4°, respectively). The results of the present study indicate that small changes in saddle height affected GE and lower limb kinematics The observed changes in lower limb kinematics could justify, in part, the GE changes. Further research should evaluate long-term effects of these small modifications in the seat height on GE and lower limb kinematics.

Sodium nitrate supplementation does not enhance performance of endurance athletes.

PURPOSE: Supplementation with inorganic nitrate has been suggested to be an ergogenic aid for athletes as nitric oxide donor. The purpose of this study was to determine whether ingestion of inorganic sodium nitrate benefits well-trained athletes performing a 40-min exercise test in laboratory conditions. In addition, we investigated the effect of this supplement on plasma levels of endothelin-1 (ET-1) and in nitrated proteins. METHODS: Thirteen trained athletes participated in this randomized, double-blind, crossover study. They performed a 40-min cycle ergometer distance-trial test after two 3-d periods of dietary supplementation with sodium nitrate (10 mg·kg of body mass) or placebo. RESULTS: Concentration of plasma nitrate (256 ± 35 µM) and nitrite (334 ± 86 nM) increased significantly (P < 0.05) after nitrate supplementation compared with placebo (nitrate: 44 ± 11 µM; nitrite: 187 ± 43 nM). In terms of exercise performance, there were no differences in either the mean distance (nitrate: 26.4 ± 1.1 km; placebo: 26.3 ± 1.2 km; P = 0.61) or mean power output (nitrate: 258 ± 28 W; placebo: 257 ± 28 W; P = 0.89) between treatments. Plasma ET-1 increased significantly (P < 0.05) just after exercise in nitrate (4.0 ± 0.8 pg·mL) and placebo (2.4 ± 0.4 pg·mL) conditions. This increase was significantly greater (P < 0.05) in the nitrate group. Levels of nitrated proteins did not differ between treatments (nitrate: preexercise, 91% ± 23%; postexercise, 81% ± 23%; placebo: preexercise, 95% ± 20%; postexercise, 99% ± 19%). CONCLUSION: Sodium nitrate supplementation did not improve a 40-min distance-trial performance in endurance athletes. In addition, concentration of plasma ET-1 increased significantly after exercise after supplementation with sodium nitrate.

Influence of saddle height on lower limb kinematics in well-trained cyclists: static vs. dynamic evaluation in bike fitting.

In cycling, proper saddle height is important because it contributes to the mechanical work of the lower limb joints, thus altering pedaling efficiency. The appropriate method to select optimal saddle height is still unknown. This study was conducted to compare a static (anthropometric measurements) vs. a dynamic method (2D analysis) to adjust saddle height. Therefore, an examination of the relationship between saddle height, anthropometrics, pedaling angles, and hamstring flexibility was carried out. Saddle height outside of the recommended range (106-109% of inseam length) was observed in 56.5% of the subjects. Inappropriate knee flexion angles using the dynamic method were observed in 26% of subjects. The results of this study support the concept that adjusting saddle height to 106-109% of inseam length may not ensure an optimal knee flexion (30-40°). To solve these discrepancies, we applied a multiple linear regression to study the relationship between anthropometrics, pedaling angles, and saddle height. The results support the contention that saddle height, inseam length, and knee angle are highly related (R = 0.963, p < 0.001). We propose a novel equation that relates these factors to recommend an optimal saddle height (108.6-110.4% of inseam length).