Table 1.

Investigated muscles and their function (Schünke et al., 2005).

Muscle	Abbreviation	Function
M. flexor digitorum superficialis	FDS	Wrist flexion; flexion of the metacarpophalangeal and the proximal interphalangeal joints of index, middle, ring, and little finger
M. flexor digitorum profundus	FDP	Wrist flexion; flexion of the metacarpophalangeal, the proximal interphalangeal, and the distal interphalangeal joints of index, middle, ring, and little finger
M. extensor digitorum	ED	Extension of the metacarpophalangeal, the proximal interphalangeal, and the distal interphalangeal joints of index, middle, ring, and little finger
M. extensor indicis proprius	EIP	Extension of the metacarpophalangeal, proximal interphalangeal, and distal interphalangeal joints of the index finger
Mm. interossei dorsales I/II	FDI/SDI	Flexion of the metacarpophalangeal joints of the index and middle finger; extension and abduction of the proximal and the distal interphalangeal joints of the index and middle finger