Wyniki wyszukiwania - BazTech

Ograniczanie wyników

2 Acta of Bioengineering and Biomechanics

2 2022

Znaleziono wyników: 2

Liczba wyników na stronie

Wyniki wyszukiwania

Sortuj według:

Ogranicz wyniki do:

Identification of muscle movements and activity by experimental methods for selected cases – stage#1

Dejneka Aleksandra, Małachowski Jerzy, Mazurkiewicz Łukasz

Acta of Bioengineering and Biomechanics

2022

Vol. 24, no. 3

69--82

The aim of this study was to determine the position where the most activated and isolated individual muscles were. In the next steps, the selected limb positions will be used to determine the maximum values of isometric forces of the individual muscle heads based on the Hill model. Methods: In order to determine the sought muscle activation, an electromyograph was used. Isometric contraction measurements were carried out for seven series of tests. Isometric contraction was performed as 100% MVC. Results: For the long head of the biceps muscle, in the case of bending in the shoulder joint, angle of 75° was selected and for abduction in the shoulder joint – 90°. Internal rotation in the shoulder joint was omitted because of lower activation values. For the short head of the biceps muscle, the angle characterized by the greatest activity of the head was the angle of 115° in flexion at the elbow joint. The selected angle was 30° for shoulder extension and 110° for shoulder adduction. For the lateral head of the triceps brachial muscle, measurements showed that the angle at which the lateral head was most activated is 115°. Conclusions: The aim of this study was to determine the positions of the arm muscles that activate and isolate individual heads the most. The research presented and achieved results concern one specific person for whom a personalized numerical model was developed to represent the flexion-extension movement at the elbow joint. The performed tests can also be a preliminary assessment of the upper limb positions, for which wider conclusions could be drawn in the case of measurements on a larger number of participants.

Identification of muscle movements and activity by experimental methods for selected cases – stage #2

Dejneka Aleksandra, Małachowski Jerzy, Mazurkiewicz Łukasz

Acta of Bioengineering and Biomechanics

2022

Vol. 24, no. 4

3--11

The aim of the performed tests and static measurements was to determine the torque and to determine the activity curve for individual muscle heads during the flexion-extension movement in the elbow joint. Methods: Both heads of the biceps branchial muscle and the triceps muscle of the arm – long head and lateral head – were examined. Static measurements were carried out for four selected positions of the upper limb. For each pose, a measurement series consisting of five attempts of ten seconds of effort was performed. Isometric contraction was performed as 100% of the maximum voluntary MVC contraction. Dynamic measurements were carried out when working in isokinetic conditions. In both stages, an EMG and a Biodex isokinetic dynamometer were used. Results: During the analyses, it was assumed that the average value of the torque is equal to the approximate value of the torque of a given head under static conditions. The value of the torque of the biceps brachial muscle, long head was 48.04 Nm and for the short head – 45.82 Nm. For the triceps muscle of the long head, this value was 52.52 Nm and for the lateral head – 38.06 Nm. On the basis of dynamic measurements, four activation curves were determined for each of the heads during the 7-second task. For the curves, the sum value of muscle activity in a given period of time was calculated as the area under the curve. Conclusions: Both parts of the series of articles present a series of experimental studies conducted in order to determine the parameters for one patient, for whom a personalized numerical model of the upper limb was ultimately created. Static measurements were carried out to determine the maximum values of the moments of forces. Dynamic measurements allowed for the determination of activity curves during the movement of the upper limb.