Strength training is commonly performed at two different knee flexion amplitudes: partial (to 90 degrees) or total (to 140 degrees). During these amplitudes, both the pelvis and the tibia are moved to ensure control of the center of gravity and displacement of the external overload. Forward or backward movement of the pelvic tilt may indirectly influence the internal load on the spine. Objectiv...

McBride, JM, Blow, D, Kirby, TJ, Haines, TL, Dayne AM, and Triplett, NT. Relationship between maximal squat strength and five, ten, and forty yard sprint times. J Strength Cond Res 23(6): 1633–1636, 2009—The purpose of this investigation was to examine the relationship between maximal squat strength and sprinting times. Seventeen Division I-AA male football athletes (height = 1.78 6 0.04 m, bod...

purpose: low back pain is one of the most common musculoskeletal disorders, and lifting is one of its risk factors. the activities of lumbar muscles as the main muscles involved in lifting are important with regard to identification of the allowable limits and the injury mechanisms as well as the motor control aspects. this study aimed to investigate the effects of the lifting speed on the lumb...

conclusions our observations add to the knowledge base of the various causes of meniscus tears; this study also revealed that socio-cultural factors influence and contribute to the mechanism of various types of knee injury. patients and methods this retrospective study was conducted in a tertiary care orthopaedic hospital which caters to a population of 10 million people. we assessed 120 non-at...

BACKGROUND Vertical jump tests are used in athletics and rehabilitation to measure physical performance in people of different age ranges and fitness. Jumping ability can be analyzed through different variables, and the most commonly used are fly time and jump height. They can be obtained by a variety of measuring devices, but most are limited to laboratory use only. The current generation of s...

[Purpose] This study evaluated the effective selective activation method of the vastus medialis oblique for knee joint stabilization in patients with patellofemoral pain syndrome. [Subjects and Methods] Fifteen healthy college students (9 males, 6 females); mean age, height, and weight: 22.2 years, 167.8 cm, and 61.4 kg, respectively) participated. The knee angle was held at 60°. Muscle activit...

The present study aimed (1) to compare loaded squat jump performance after an acute and chronic exposure to a moderate natural altitude between normoxia and hypobaric hypoxia conditions, and (2) to analyze the effect of an altitude training camp on loaded jump squat development. Sixteen male swimmers (17.1 ± 0.8 years) took part in a 17-day training camp at a natural moderate altitude. They wer...

Identification of the hip joint centre (HJC) is important in the biomechanical examination of human movement. However, there is yet to be any published information regarding the influence of different HJC locations on hip and knee joint kinetics during functional tasks. This study aimed to examine the influence of four different HJC techniques on 3-D hip and knee joint kinetics/kinematics durin...

[Purpose] This study aimed to examine changes in lower extremity kinematics in the sagittal plane during downward squatting by subjects with pronated feet. [Subjects and Methods] This study selected 10 subjects each with normal and pronated feet using a navicular drop test. The subjects performed downward squatting, in which the knee joints flex 90° in a standing position. We recorded the angle...

Although the squat exercise is considered essential for optimal athletic performance, controversy exists regarding the effect on knee stability. The purpose of this prospective study was to determine the effect of squat exercises on in vivo knee joint stability of professional football players. Thirty-two subjects with normal knees participated in a 21-week off-season training program. Subjects...