Studies on muscular strength-myogram (MSMG). Part 1. A new device of apparatus for measuring muscular strength-myogram

1. A new apparatus, consisting of a strain gauge and a carrier amplifier, was devised for measuring back muscular and shoulder arms strength by the author. This apparatus was applied for analysing myogenic disorder related to muscular fatigue or pain. 2. Muscular strength with load and its myogram were recorded simultaneously, and their changes during the exertion were analysed. 3. Muscular strength-myograms of sternocleidomastoid muscle, upper trapezius muscle, deltoid muscle, rhomboid muscle and lumbodorsal muscle were observed from the back muscular strength-myogram, and those of teres minor muscle and major pectoral muscle from the shoulder arm strength-myogram. 4. It seemed paradoxically that the amplitude of action myogram increased in proportion to the grade of lowering of muscular strength caused by muscular fatigue or pain.

Normal and abnormal motion of the shoulder

The roentgenographic parameters of motion in normal and abnormal shoulders, including the movement of the scapula, arm angle, glenohumeral angle, scapulothoracic angle, excursion of the humeral head, and instant center of motion for abduction in the plane of the scapula, were determined in twelve normal subjects and fifteen patients. The scapula rotated externally with abduction. The ratio of glenohumeral to scapulothoracic movement was 5:4 after about 30 degrees of abduction. The center of rotation of the glenohumeral joint for abduction in the plane of the scapula was located within six millimeters of the geometric center of the humeral ball. The average excursion of the humeral ball on the face of the glenoid in the superoinferior plane between each 30-degree arc of motion was less than 1.5 millimeters in normal subjects. Significant previous injury resulting in abnormal mechanics of the shoulder joint was associated with abnormal values for excursion of the instant center and of the humeral head. An abnormal glenohumeral-to-scapulothoracic ratio was associated with significant pain in the shoulder. The fact that these various parameters were sensitive indicators of normal and abnormal motion raises the possibility of diagnostic clinical application.

Prolactin release in dairy heifers relative to duration of teat stimulation

Experiments have shown that the prolactin response specific to sustained teat stimulation is strictly dependent upon the duration of stimulation. There is some evidence for assuming two principally different patterns of prolactin response, namely high sensitivity to the stimulus with an initial maximal response, and poor sensitivity to the stimulus with a gradually intensifying response. Hyperstimulation of teats results in relative refractoriness of neural receptors for specific prolactin impulses. Refractoriness of one teat leads to a reduction in the release of prolactin which can be overcome by the stimulation of another as yet unstimulated teat.

Observations on the flexed-arm hang test for women

The AAHPER and an experimental flexed-arm hang test were both significantly related to dynamic arm and shoulder girdle endurance for 43 college women, while little relationship existed between either flexed-arm hang test and grip strength.