Final answer:
The statement that contractures are a result of a total lack of ATP is true. ATP's role is critical for both muscle contraction and relaxation, and its absence can lead to a state of continuous contraction or contracture.
Step-by-step explanation:
The statement 'Contractures are a result of a total lack of ATP' is True. Contractures can occur when muscle fibers are unable to relax due to a lack of ATP. Normally, ATP is required for both muscle contraction and relaxation. During contraction, ATP is used to power the sliding of actin and myosin filaments past each other. In relaxation, ATP is necessary for the dissociation of the actin-myosin cross-bridges, essentially 'unlocking' the fibers so they can elongate back into their uncontracted state.
However, when ATP is completely depleted, as in the event of death, myosin heads remain attached to actin, unable to release. This results in a fixed, contracted state known as rigor mortis. Hence, in a living individual, extreme ATP depletion would also lead to continued muscle contraction, or contracture, due to the inability of the muscle fibers to relax without ATP.