Thanks for query on HCM.
Most likely it is due to myalgia
. (muscular pain
It usually occurs due to muscle sprain after improper posture in sleeping,sitting,working.
Start nsaid with muscle relaxant
.Apply nsaid gel locally.
,calcium,vitamin-e,minerals will be helpful.
It will recover within 5 to 7 days after these treatment otherwise go for certain investigations and proper medical management under guidance of orthopedician.