To provide a bed mattress obtained using the measurement of a muscular strength, its choice, and a suitable arrangement method in this invention.

This invention evaluates whether a bed mattress is suitable for a user by measuring the ability of lower limbs when the user lies supine on the bed mattress. The bed mattress of this invention includes a composite material structure which is placed on a bed surface, a bed base, and between the bed surface and the bed base. The bed mattress suitable for the user can be provided by adjusting the quality of material, hardness, and thickness of the composite material structure. In addition to this, also since the choice of the bed mattress and a suitable arrangement method using the measurement of the muscular strength are provided in this invention, the user or a consumer can choose a suitable bed mattress according to the demand effectively and for economic benefit.