(Greek: no muscle)

amyoesthesia (s) (noun), amyoesthesias (pl)
Absence of muscle sensations: Darin's amyoesthesia resulted in his not being able to sense motions, weights, or balances.
amyoesthesis (s) (noun), amyoestheses (pl)
The lack, or loss, of muscular sense or perception: Muriel's amyoesthesis made it impossible for her to be aware of movements or even of different positions.
amyoplasia (s) (noun), amyoplasias (pl)
Deficient formation of muscle tissue and a lack of muscle growth: As a result of significant malnutrition, Irvin had a form of acquired amyoplasia in his muscle tissues.
amyostasia (s) (noun) (no plural)
Difficulty in standing because of a tremor of the muscles or as a result of a lack of coordination: The elderly Mrs. Hathaway had to use a wheelchair to get around sometimes because of her amyostasia which prevented her to be on her feet and be upright.
amyotaxia, amyotaxy
Muscular incoordination attributable to cerebellar lesions; ataxia.
amyotonia (s) (noun), amyotonias (pl)
Generalized absence of muscle tone; a floppiness of the muscles: Amyotonias are usually associated with flabby muscles and an increased range of passive movements at the joints.
amyotonic (adjective), more amyotonic, most amyotonic
A reference to a lack of muscle tension: Amyotonic muscles may result from any of several rare congenital diseases characterized by general hypotonia of the skeletal muscles."
amyotrophia (s) (noun), amyotrophias (pl)
Lacking in muscle size and number of muscle fibers that takes place with aging, reduction in blood supply, or following physical inactivity, and malnutrition: The amyotrophia that anyone has is often a progressive deficiency of muscle tissue; especially, because that person doesn't move around and use his or her muscles.

There are numerous causes for the amyotrophias of muscles; including, chronic malnutrition, immobilizations, and denervation which is a loss of nerve supplies that may be caused by a disease; for example, in polio where the death of motor neurons causes the denervation of muscle fibers.

amyotrophy (s) (noun), amyotrophies (pl)
Muscular degeneration or away or the wasting away of the muscles.