ABSTRACT
Variable resistance implemented through concurrent use of rubber-based resistance bands and free weights is commonly used in training athletes. The purpose of this study was to examine the consistency of rubber-based resistance (RBR) band loading patterns across four distributors. Bands (n = 141) were obtained from online distributors (Rogue Fitness, EliteFTS, RubberBanditz, and Power Systems) across a spectrum of available widths (0.635, 1.270, 2.860, 4.450, 6.350, and 10.160 cm). At least five bands for each width were stretched in 5 cm increments from resting (100 cm) to twice resting length (200 cm) while tensile resistance was measured using a load cell integrated with a digital controller. Each band was tested twice on non-consecutive days producing an intertrial intraclass correlational coefficient (ICC) between 0.93â»0.99 with a grand mean ICC across all repeated measures of 0.99. Statistical differences were observed in mean resistance for bands of equal thickness across distributors. Significant correlations were found between a range of tensile load expressed as a total load and band thickness (r = 0.658) and when expressed as a percentage (r = -0.386). This study is useful for strength and conditioning professionals and clinicians who should be cognizant of loading variability within both bandwidths and between distributors.
ABSTRACT
CONTEXT: Decreased flexibility in muscles and joints of lower extremities is commonly observed in runners. Understanding the effect of decreased flexibility on knee walking kinematics in runners is important because, over time, altered gait patterns can make runners vulnerable to overuse injuries or degenerative pathologies. OBJECTIVES: To compare hamstring and iliotibial-band (ITB) flexibility and knee kinematics in runners and nonrunners. DESIGN: A descriptive, comparative laboratory study. SETTING: Hamstring and ITB flexibility were measured with the active knee-extension test and the modified Ober test, respectively, in both groups of participants. Three-dimensional (3D) walking kinematic data were then recorded at the knee using a motiontracking system. PARTICIPANTS: 18 runners and 16 nonrunners. MAIN OUTCOME MEASURES: Knee-extension angle (hamstring flexibility) and hip-adduction angle (ITB flexibility). Knee kinematic parameters of interest included knee angle at initial contact, peak knee angles, and knee-angle range in all planes of movement. RESULTS: The runners had a significantly less flexible ITB than the nonrunners (hip adduction [-] and adduction [+] angles, 3.1° ± 5.6° vs -.4° ± 4.5°; P < .001). The runners demonstrated a greater mean tibial external-rotation angle at initial contact (7.3° ± 5.8° vs 2.0° ± 4.0°; P = .01) and a smaller mean peak tibial internal-rotation angle (-1.6° ± 3.0° vs -4.2° ± 3.2°; P = .04) than the nonrunners. CONCLUSION: This study provides new insight into the relationship between muscle flexibility and 3D knee kinematics in runners. This supports the premise that there is an association between muscle flexibility and transverse-plane knee kinematics in this population.
Subject(s)
Fascia Lata/physiology , Knee Joint/physiology , Muscle, Skeletal/physiology , Running/physiology , Walking/physiology , Adult , Biomechanical Phenomena , Gait , Hip Joint/physiology , Humans , Middle Aged , Range of Motion, Articular , Rotation , ThighABSTRACT
Objetivos: Determinar la relación de la distancia de la piel al espacio epidural lumbar a nivel de los interespacios L2-L3, en las pacientes programados para cesárea electiva o de emergencia en el Hospital Nacional Dos de Mayo, durante, el periodo de estudio. Material y métodos: Se realizó un estudio observacional, descriptivo, prospectivo y transversal. Se tomaron los datos antropométricos de las pacientes cesareadas programadas, que fueron sometidas a bloqueos epidurales lumbares a nivel de los interespacios L2-L3 en el periodo que corresponde al estudio. Resultados: El motivo de cesárea más frecuente; fue el antecedente de cesárea anterior en el 28 por ciento de los casos. El 29.7 por ciento de las pacientes tuvieron edades comprendidas entre los 26 a 30 años. El 68.6 por ciento de las gestantes tuvieron pesos comprendidos entre los 60 y 80 kilos. El 61 por ciento de las gestantes tuvieron talla entre 1.51 a 160mt. El 68.6 por ciento de las gestantes tuvieron índice de masa corporal entre 26 y 30. Conclusiones: Existe relación estadísticamente significativa de la distancia de la piel al espacio epidural lumbar a nivel de los interespacios L2-L3, en las pacientes programadas para cesárea, es decir, a mayores valores de los datos antropométricos mayores son las medias de la distancia de la piel al espacio epidural (P<0.05).