Natalia Romero-Franco

Effects of proprioceptive training program on core stability and center of gravity control in sprinters.

Abstract Romero-Franco N, Martínez-López EJ, Lomas-Vega R, Hita-Contreras F, and Martínez-Amat A. Effects of proprioceptive training program on core stability and center of gravity control in sprinters. J Strength Cond Res 26(8): 2071–2077, 2012—The purpose of this study was to determinate the effect of a 6-week specific-sprinter proprioceptive training program on core stability and gravity center control in sprinters. Thirty-three athletes (age = 21.82 ± 4.84 years, height = 1.76 ± 0.07 m, weight = 67.82 ± 08.04 kg, body mass index = 21.89 ± 2.37 kg·m−2) from sprint disciplines were divided into a control (n = 17) and experimental (n = 16) groups. A 30-minute proprioceptive training program was included in the experimental group training sessions, and it was performed for 6 weeks, 3 times each week. This program included 5 exercises with the BOSU and Swiss ball as unstable training tools that were designed to reproduce different moments of the technique of a sprint race. Stability with eyes open (EO) and eyes closed, postural stability, and gravity center control were assessed before and after the training program. Analyses of covariance (&agr; = 0.05) revealed significant differences in stability in the medial-lateral plane with EO, gravity center control in the right direction and gravity center control in the back direction after the exercise intervention in the experimental athletes. Nevertheless, no other significant differences were demonstrated. A sprinter-specific proprioceptive training program provided postural stability with EO and gravity center control measures improvements, although it is not clear if the effect of training would transfer to the general population.

Experienced versus Inexperienced Interexaminer Reliability on Location and Classification of Myofascial Trigger Point Palpation to Diagnose Lateral Epicondylalgia: An Observational Cross-Sectional Study.

The purpose was to evaluate the interexaminer reliability of experienced and inexperienced examiners on location and classification of myofascial trigger points (MTrPs) in two epicondylar muscles and the association between the MTrP found and the diagnosis of lateral epicondylalgia (LE). Fifty-two pianists (some suffered LE) voluntarily participated in the study. Three physiotherapists (one inexperienced in myofascial pain) examined, located, and marked MTrPs in the extensor carpi radialis brevis (ECRB) and extensor digitorum communis (EDC) muscles. Forearms were photographed and analyzed to establish the degree of agreement on MTrPs diagnosis. Data showed 81.73% and 77.88% of agreement on MTrP classification and 85.58% and 72.12% on MTrP location between the expert evaluators for ECRB and EDC, respectively. The agreement on MTrP classification between experienced and inexperienced examiners was 54.81% and 51.92% for ECRB and 50.00% and 55.77% for EDC. Also, agreement on MTrP location was 54.81% and 60.58% for ECRB and 48.08% and 48.08% for EDC. A strong association was found between presence of relevant MTrPs, LE diagnosis, and forearm pain when the examiners were experts. The analysis of location and classification of MTrPs in the epicondylar muscles through physical examination by experienced evaluators is reliable, reproducible, and suitable for diagnosing LE.

Short-term Effects of a Proprioceptive Training Session with Unstable Platforms on the Monopodal Stabilometry of Athletes.

To analyze the short-term effects of a proprioceptive session on the monopodal stabilometry of athletes. [Subjects] Thirty-seven athletes were divided into a control group (n=17) and an experimental group (n=20). [Methods] Both groups performed a conventional warm-up, after which a 25-minute proprioceptive session on ustable platforms was carried out only by the experimental group. Before the training session, all athletes carried out a single-leg stabilometry test which was repeated just after training, 30 minutes, 1 hour, 6 hours and 24 hours later. [Results] Analysis of covariance (α=0.05) revealed that the experimental group had lower values than the control group in length and velocity of center of pressure (CoP) of left-monopodal stance and in velocity of CoP of right-monopodal stance in post-training measurements. Also, the experimental group had values closer to zero for the CoP position in the mediolateral and anteroposterior directions of left-monopodal stance (Xmeanl and Ymeanl) and the anteroposterior direction in on right-monopodal stance (Ymeanr) in post-training measurements. Within-group analysis of Xmeanl and Ymeanl, length and velocity of CoP in right-monopodal stance showed continuous fluctuations of values between sequential measurements in the control group. [Conclusion] Proprioceptive training on unstable platfoms after a warm-up stabilizes the position of CoP in the anteroposterior and mediolateral directions and decreases CoP movements in short-term monopodal stability of athletes.

Sprint performance and mechanical outputs computed with an iPhone app: Comparison with existing reference methods

Abstract The purpose of this study was to assess validity and reliability of sprint performance outcomes measured with an iPhone application (named: MySprint) and existing field methods (i.e. timing photocells and radar gun). To do this, 12 highly trained male sprinters performed 6 maximal 40-m sprints during a single session which were simultaneously timed using 7 pairs of timing photocells, a radar gun and a newly developed iPhone app based on high-speed video recording. Several split times as well as mechanical outputs computed from the model proposed by Samozino et al. [(2015). A simple method for measuring power, force, velocity properties, and mechanical effectiveness in sprint running. Scandinavian Journal of Medicine & Science in Sports. https://doi.org/10.1111/sms.12490] were then measured by each system, and values were compared for validity and reliability purposes. First, there was an almost perfect correlation between the values of time for each split of the 40-m sprint measured with MySprint and the timing photocells (r = 0.989–0.999, standard error of estimate = 0.007–0.015 s, intraclass correlation coefficient (ICC) = 1.0). Second, almost perfect associations were observed for the maximal theoretical horizontal force (F0), the maximal theoretical velocity (V0), the maximal power (Pmax) and the mechanical effectiveness (DRF – decrease in the ratio of force over acceleration) measured with the app and the radar gun (r = 0.974–0.999, ICC = 0.987–1.00). Finally, when analysing the performance outputs of the six different sprints of each athlete, almost identical levels of reliability were observed as revealed by the coefficient of variation (MySprint: CV = 0.027–0.14%; reference systems: CV = 0.028–0.11%). Results on the present study showed that sprint performance can be evaluated in a valid and reliable way using a novel iPhone app.

Postural Stability and Subsequent Sports Injuries during Indoor Season of Athletes.

[Purpose] The aim of this study was to analyze stabilometry in athletes during an indoor season in order to determine whether injured athletes show different stabilometric values before injury than non-injured athletes in two different training periods (volume and pre-competition periods). [Subjects] The subjects were 51 athletes from Unicaja athletic club who trained regularly. [Methods] At the end of the preseason and volume periods, athletes were subjected to bipodal and monopodal stabilometry. In addition, all injuries happening in the periods after performing stabilometry (volume and pre-competition periods) were tracked. [Results] Variance analysis of bipodal stabilometric measurements taken at the end of the preseason period showed that athletes with higher values for the center-of-pressure spread variables suffered injuries during the volume period. The right-leg monopodal stabilometric measurements taken at the end of the volume period showed that athletes with higher values in the center-of-pressure position variables suffered injuries during the pre-competition period. [Conclusion] Athletes showing the worst values for center-of-pressure spread variables are more prone to sports injuries in the subsequent training period. In monopodal measurements, athletes with poorer mediolateral stability were more prone to injuries in the subsequent training period.

Unipedal Postural Balance and Countermovement Jumps After a Warm-up and Plyometric Training Session: A Randomized Controlled Trial

Abstract Romero-Franco, N and Jiménez-Reyes, P. Unipedal postural balance and countermovement jumps after a warm-up and plyometric training session: A randomized controlled trial. J Strength Cond Res 29(11): 3216–3222, 2015—The purpose of this study was to analyze the immediate effects of a plyometric training protocol on unipedal postural balance and countermovement jumps. In addition, we analyzed the effects of a warm-up on these parameters. Thirty-two amateur male sprinters (24.9 ± 4.1 years; 72.3 ± 10.7 kg; 1.78 ± 0.05 m; 22.6 ± 3.3 kg·m−2) were randomly sorted into a control group (n = 16) (they did not perform any physical activity) and a plyometric training group (n = 16) (they performed a 15-minute warm-up and a high-intensity plyometric protocol consisting of 10 sets of 15 vertical jumps). Before and after the warm-up, and immediately after and 5 minutes after the plyometric protocol, all athletes indicated the perceived exertion on calf and quad regions on a scale from 0 (no exertion) to 10 (maximum exertion). They also carried out a maximum countermovement jump and a unipedal postural balance test (athletes would remain as still as possible for 15 seconds in a left leg and right leg support stance). Results showed that, in the plyometric group, length and velocity of center-of-pressure movement in right leg support stance increased compared with baseline (p = 0.001 and p = 0.004, respectively) and to the control group (p = 0.035 and p = 0.029, respectively) immediately after the plyometric protocol. In addition, the countermovement jump height decreased right after the plyometric protocol (p < 0.001). The perceived exertion on calf and quad regions increased after the plyometry (p < 0.001). Five minutes later, these parameters remained deteriorated despite a slight recovery (length: p = 0.044; velocity: p = 0.05; countermovement jump height: p < 0.001; local exertion: p < 0.001). Data also showed that countermovement jump height improved after the warm-up (p = 0.021), but unipedal postural balance remained unaltered. As a conclusion, high-intensity plyometric exercises blunt unipedal postural balance and countermovement jump performance. The deterioration lasts at least 5 minutes, which may influence future exercises in the training session. Coaches should plan the training routine according to the immediate effects of plyometry on postural balance and vertical jumps, which play a role in injury prevention and sports performance.

Validity and Reliability of a Digital Inclinometer to Assess Knee Joint Position Sense in a Closed Kinetic Chain

CONTEXT Knee joint position sense (JPS) is a key parameter for optimum performance in many sports but is frequently negatively affected by injuries and/or fatigue during training sessions. Although evaluation of JPS may provide key information to reduce the risk of injury, it often requires expensive and/or complex tools that make monitoring proprioceptive deterioration difficult. OBJECTIVE To analyze the validity and reliability of a digital inclinometer to measure knee JPS in a closed kinetic chain (CKC). DESIGN The validity and intertester and intratester reliability of a digital inclinometer for measuring knee JPS were assessed. SETTING Biomechanics laboratory. PARTICIPANTS 10 athletes (5 men and 5 women; 26.2 ± 1.3 y, 71.7 ± 12.4 kg; 1.75 ± 0.09 m; 23.5 ± 3.9 kg/m2). INTERVENTION Knee JPS was measured in a CKC. MAIN OUTCOME MEASURES Absolute angular error (AAE) of knee JPS in a CKC. RESULTS Intraclass correlation coefficient (ICC) and standard error of the mean (SEM) were calculated to determine the validity and reliability of the inclinometer. Data showed that the inclinometer had a high level of validity compared with an isokinetic dynamometer (ICC = 1.0, SEM = 1.39, p < 0.001), and there was very good intra- and inter-tester reliability for reading the inclinometer (ICC = 1.0, SEM = 0.85, p < 0.001). Compared with AutoCAD video analysis, inclinometer validity was very high (ICC = 0.980, SEM = 3.46, p < 0.001) for measuring AAE during knee JPS in a CKC. In addition, the intertester reliability of the inclinometer for obtaining AAE was very high (ICC = .994, SEM = 1.67, p < 0.001). CONCLUSION The inclinometer provides a valid and reliable method for assessing knee JPS in a CKC. Health and sports professionals could take advantage of this tool to monitor proprioceptive deterioration in athletes.