A large inter-individual variation is seen in muscle fascicle length of the athletes but the reasons for this phenomenon are unclear. The purpose of this study was to determine whether genetic factors contribute to the variances in muscle architectural characteristics. Nine monozygous twin pairs (3 males and 6 females), mean age 23 years (range 17-40) were studied. Fascicle length, pennation an...

Alterations in the location of the hip center may change the lengths and moment arms of the muscles, and thereby affect their capacity to generate force and moment about the hip. This study demonstrates some of the differences between compensating and not compensating for changes in muscle length that arise from displacement of the hip center. A computer model was developed to estimate the maxi...

Isolated rat papillary muscles of the right ventricle were used to discover the origin of reduced myocardial efficiency in chronic heart failure. Right ventricular hypertrophy was induced by monocrotaline injection, causing pulmonary hypertension. Control (n = 7) and hypertrophied (n = 11) papillary muscles were subjected to sinusoidal length changes at 37 degrees C and 5 Hz with a peak-to-peak...

OBJECTIVES/HYPOTHESIS Selective reinnervation of the posterior cricoarytenoid muscle with a single phrenic nerve rootlet has been shown to restore physiologic motion in animal models. However, clinical translation of this work is challenged by the limited knowledge of the cervical anatomy of the phrenic nerve. STUDY DESIGN Prospective collaborative study. METHODS Dissection of 111 cadaveric...

Pectoral fins are one of the major features of locomotor design in ray-finned fishes and exhibit a well-documented phylogenetic transition from basal to derived clades. In percomorph fishes, the pectoral fins are often used to generate propulsive force via oscillatory movements, and pectoral fin propulsion in this relatively derived clade has been analyzed extensively. However, in the plesiomor...

[Purpose] The aim of this study was to examine the effect of trunk stability exercise and combined exercise program on pain, flexibility, and static balance in chronic low back pain patients. [Subjects and Methods] Thirty persons diagnosed with chronic low back pain were divided into a trunk stability exercise group and a combined exercise group and then conducted exercise for six weeks. [Resul...

Pneumatic artificial muscles (PAMs) are becoming more commonly used as actuators in modern robotics. The most made and common type of these artificial muscles in use is the McKibben artificial muscle that was developed in 1950’s. This paper presents the geometric model of PAM and different Matlab models for pneumatic artificial muscles. The aim of our models is to relate the pressure and length...

Quantitative descriptions of muscle architecture are needed to characterize the force-generating capabilities of muscles. This study reports the architecture of three major trunk muscles: the rectus abdominis, quadratus lumborum, and three columns of the erector spinae (spinalis thoracis, longissimus thoracis and iliocostalis lumborum). Musculotendon lengths, muscle lengths, fascicle lengths, s...