P. Sainz de Baranda

Chronic flexibility improvement after 12 week of stretching program utilizing the ACSM recommendations: hamstring flexibility.

The ACSM flexibility training recommendations emphasize proper stretching of muscles supporting the major joints, but there is a little evidence to support this recommendation in terms of effectiveness, and which stretching parameters (technique and single stretch duration) are more adequate. A randomized controlled clinical trial design was use to investigate whether the ACSM flexibility training recommendation parameters improve hip flexion range of motion. A total of 173 subjects, 122 men (21.3+/-2.5 years; 176.33+/-8.35 cm; 74.42+/-10.80 kg) and 51 women (20.7+/-1.6 years; 163.43+/-6.57 cm; 60.12+/-7.88 kg), classified as recreationally active young adult university students were randomly assigned to 1 of 7 groups: 1 control group (no stretching) or 1 of 6 stretching groups. All stretching groups performed 12 weeks of flexibility training with a consistent stretch daily dose (180 s) and frequency (3 days per week) parameters and different stretch technique (passive or active) and single stretch duration (15, 30, or 45 s). Hip flexion passive range of motion (PROM) was determined through the bilateral straight-leg raise test before, during (at 4 and 8 weeks), and after the program (12 weeks). All stretching groups performed hip flexion PROM after flexibility training. A significant improvement was identified in mean PROM for each stretching group, but no significant differences were found between stretch technique and single stretch duration (p>0.05). The control groups mean PROM decreased (Delta PROM: -0.08 degrees, 95% confidence interval [CI]=-2.3 to 5.3), whereas all stretching groups increased PROM (Delta PROM: 15.14 degrees, 95% CI=10.19 to 23.56) in hip flexion after 12 weeks of stretching (p<0.05). The present study suggests that the current ACSM flexibility training recommendations are effective for improving hip flexion ROM in recreationally active young adults.

Reproducibility and criterion-related validity of the sit and reach test and toe touch test for estimating hamstring flexibility in recreationally active young adults

OBJECTIVE 1) to examine the test-retest reproducibility and criterion-related validity of the sit and reach test (SRT) and the toe touch test (TT) for estimating hamstring flexibility measured through the passive straight leg raise test (PSLR); and 2) to determine whether the SRT cut-off scores may be used for the TT test to identify participants in this sample of young healthy adults as having short hamstring flexibility. DESIGN Test-retest design. SETTING Controlled laboratory environment. PARTICIPANTS 243 active recreationally young adults. MAIN OUTCOME MEASURES Participants performed the SRT, the TT test and PSLR twice in a randomized order with a 4-week interval between trials. Reproducibility was examined using typical percentage error (coefficient of variation [CV]) and intraclass correlation coefficient (ICC) as well as their respective confidence limits. Regression and Kappa correlation statistical analyses were performed to study the association of the SRT and TT test with the PSLR test and the 95% limits of agreement (LoA) between SRT and TT test were calculated to explore differences in the mean differences between these measurements. RESULTS The finding showed acceptable reproducibility measures for SRT (8.74% CV; 0.92 ICC), TT test (9.86% CV; 0.89 ICC) and PSLR (5.46% CV; 0.85 ICC). The SRT (R² = 0.63) and TT test (R² = 0.49) were significantly associated with PSLR. The 95% LoA between SRT and TT test reported systematic bias (2.84 cm) and wide 95% random error (±9.72 cm). CONCLUSIONS Reproducibility of SRT, TT test and PSLR is acceptable and the criterion-related validity of SRT and TT test is moderate. Furthermore, the SRT cut-off scores should not be used for TT test for the detection of short hamstring muscles.

Absolute reliability of hamstring to quadriceps strength imbalance ratios calculated using peak torque, joint angle-specific torque and joint ROM-specific torque values.

The main purpose of this study was to determine the absolute reliability of conventional (H/Q(CONV)) and functional (H/Q(FUNC)) hamstring to quadriceps strength imbalance ratios calculated using peak torque values, 3 different joint angle-specific torque values (10°, 20° and 30° of knee flexion) and 4 different joint ROM-specific average torque values (0-10°, 11-20°, 21-30° and 0-30° of knee flexion) adopting a prone position in recreational athletes. A total of 50 recreational athletes completed the study. H/Q(CONV) and H/Q(FUNC) ratios were recorded at 3 different angular velocities (60, 180 and 240°/s) on 3 different occasions with a 72-96 h rest interval between consecutive testing sessions. Absolute reliability was examined through typical percentage error (CVTE), percentage change in the mean (CM) and intraclass correlations (ICC) as well as their respective confidence limits. H/Q(CONV) and H/Q(FUNC) ratios calculated using peak torque values showed moderate reliability values, with CM scores lower than 2.5%, CV(TE) values ranging from 16 to 20% and ICC values ranging from 0.3 to 0.7. However, poor absolute reliability scores were shown for H/Q(CONV) and H/Q(FUNC) ratios calculated using joint angle-specific torque values and joint ROM-specific average torque values, especially for H/Q(FUNC) ratios (CM: 1-23%; CV(TE): 22-94%; ICC: 0.1-0.7). Therefore, the present study suggests that the CV(TE) values reported for H/Q(CONV) and H/Q(FUNC) (≈18%) calculated using peak torque values may be sensitive enough to detect large changes usually observed after rehabilitation programmes but not acceptable to examine the effect of preventitive training programmes in healthy individuals. The clinical reliability of hamstring to quadriceps strength ratios calculated using joint angle-specific torque values and joint ROM-specific average torque values are questioned and should be re-evaluated in future research studies.

Fiabilidad y validez de las pruebas sit-and-reach , revisión sistemática

Resumen Las pruebas de valoracion “dedos planta” o sit-and-reach , son las que con mayor frecuencia, clinicos, entrenadores y preparadores fisico-deportivos emplean para estimar la flexibilidad de la musculatura isquiosural, Son varias las pruebas sit-and-reach descritas en la literatura cientifica, entre las que se destacan: a) el clasico sit-and-reach test, b) el V “sit-and-reach” test , c) el back-saver sit-and-reach test , d) el “modificado sit-and-reach test” y e) el toe-touch test . Existen ciertas diferencias entre ellas con respecto a la posicion del sujeto (unilateral o bilateral, sedentacion o bipedestacion, posicion de la pelvis) y el equipamiento necesario (evaluado con o sin cajon de medicion, ejecutado en una camilla, banco o suelo). La eleccion de uno u otro test va a estar en funcion de: a) la funcionalidad de su metodologia de evaluacion; b) de su fiabilidad absoluta y relativa (intra- e interexaminador) asi como c) de su validez para la estimacion de la flexibilidad isquiosural. Todo este conocimiento permitira a clinicos, entrenadores y profesionales del mundo de la actividad fisica disponer de informacion suficiente para adoptar un juicio de valor cientificamente justificado sobre que prueba de valoracion sit-and-reach utilizar para categorizar a sus deportistas-pacientes (estudio de la validez) y/o monitorizar la eficacia de los tratamientos aplicados (estudio de la fiabilidad absoluta y relativa) para el mantenimiento o mejora de la flexibilidad de la musculatura isquiosural. Los objetivos de esta revision bibliografica son analizar y comparar la fiabilidad y validez de las pruebas sit-and-reach para la estimacion de la flexibilidad de la musculatura isquiosural y lumbar.

Absolute reliability of isokinetic knee flexion and extension measurements adopting a prone position

The main purpose of this study was to determine the absolute and relative reliability of isokinetic peak torque (PT), angle of peak torque (APT), average power (PW) and total work (TW) for knee flexion and extension during concentric and eccentric actions measured in a prone position at 60, 180 and 240° s−1. A total of 50 recreational athletes completed the study. PT, APT, PW and TW for concentric and eccentric knee extension and flexion were recorded at three different angular velocities (60, 180 and 240° s−1) on three different occasions with a 72‐ to 96‐h rest interval between consecutive testing sessions. Absolute reliability was examined through typical percentage error (CVTE), percentage change in the mean (ChM) and relative reliability with intraclass correlations (ICC3,1). For both the knee extensor and flexor muscle groups, all strength data (except APT during knee flexion movements) demonstrated moderate absolute reliability (ChM < 3%; ICCs > 0·70; and CVTE < 20%) independent of the knee movement (flexion and extension), type of muscle action (concentric and eccentric) and angular velocity (60, 180 and 240° s−1). Therefore, the current study suggests that the CVTE values reported for PT (8–20%), APT (8–18%) (only during knee extension movements), PW (14–20%) and TW (12–28%) may be acceptable to detect the large changes usually observed after rehabilitation programmes, but not acceptable to examine the effect of preventative training programmes in healthy individuals.

El entrenamiento de la flexibilidad: técnicas de estiramiento

Palabras clave: Estiramiento estatico. Estiramiento dinamico. Estiramiento balistico. Facilitacion neuromuscular propioceptiva. Rutinas de estiramiento. Rango de movimiento. RESUMEN La realizacion sistematizada de rutinas de estiramiento es una practica muy comun en el ambito clinico y fisico-deportivo con el proposito principal de mantener o mejorar la amplitud de movimiento de una articulacion o conjunto de articulaciones. Ademas, los estiramientos parecen ser un medio muy indicado para el cuidado, la prevencion y el mantenimiento de las capacidades fisicas de cada individuo o para su desarrollo.

Pruebas angulares de estimación de la flexibilidad isquiosural: análisis de la fiabilidad y validez

Resumen Las pruebas de valoracion basadas en medidas angulares son empleadas frecuentemente en el ambito clinico y cientifico para estimar y monitorizar la flexibilidad de la musculatura isquiosural. Son varias las pruebas angulares descritas en la literatura cientifica, entre las que destacan: a) la prueba de elevacion de la pierna recta; b) la prueba del angulo popliteo y c) las pruebas que estudian la disposicion de la pelvis y la porcion caudal del raquis lumbar en posicion de maxima flexion de tronco, diferenciando entre “pruebas lumbo-vertical en flexion” y “pruebas lumbo-horizontal en flexion”. Se han descrito limitaciones e inconvenientes en todos los protocolos, fundamentalmente en cuanto a la posible participacion de pelvis y raquis, la posicion de la articulacion del tobillo (en flexion dorsal o flexion plantar), diferentes limites de normalidad en las exploraciones, aplicacion de distinta velocidad y fuerza en la realizacion de los test, existencia o no de calentamiento previo y variabilidad de los instrumentos empleados. La eleccion de uno u otro test debe estar basada en: a) la funcionalidad de su metodologia de evaluacion; b) su fiabilidad absoluta y relativa (intra- e interexaminador) y c) su validez para la estimacion de la flexibilidad isquiosural. Todo este conocimiento permitira disponer de informacion suficiente para adoptar un juicio de valor cientificamente justificado sobre que prueba de exploracion angular utilizar para categorizar a sus deportistas-pacientes (estudio de la validez) y/o monitorizar la eficacia de los tratamientos aplicados (estudio de la fiabilidad absoluta y relativa) para el mantenimiento o mejora de la flexibilidad de la musculatura isquiosural. Por ello, los objetivos de esta revision bibliografica son analizar y comparar la fiabilidad y validez de las pruebas angulares para la estimacion de la flexibilidad de la musculatura isquiosural.