SIMIAN CREASE: Normal palmar crease. SIMIAN CREASE: Simian crease. simian crease. A crease on the palm of the hand, so called because of its similarity to the transverse flexion crease found in some monkeys. Normally the palm of the hand at birth contains several flexion creases, two of which are separate and approx. transverse. When these two appear to fuse and form a single transverse crease, a simian crease is present.
Muscle contraction is the activation of tension-generating sites within muscle fibers. In physiology, muscle contraction does not mean muscle shortening because muscle tension can be produced without changes in muscle length such as holding a heavy book or a dumbbell at the same position.he termination of muscle contraction is followed by muscle relaxation, which is a return of the muscle fibers to their low tension-generating state. Muscle contractions can be described based on two variables: length and tension.
Concentric contractions: A concentric contraction is a type of muscle contraction where the length of the muscles shorten while undergoing tension. For example, when you pick up a curl bar and perform a biceps curl, the length of your biceps muscles shorten.Your hands start down by your sides, and ends with your hands up by your shoulders.eight training therefore, involves concentric muscle movements, voluntary eccentric muscle movements, and occasionally, involuntary eccentric movements. Isometric contractions: An isometric contraction is a type of muscle contraction where the length of the muscle doesnât change while undergoing tension.