An outstanding unanswered question in muscle physiology is concerned with the details of the molecular mechanisms involved in the generation of force. Physiological experiments on stiated muscle aimed at obtaining information at the cross bridge level are often complicated by unwanted effects which make interpretation difficult. Some of these are nonuniform sarcomere lengths, end effects due to tendons and clamping, dispersion of fiber lengths, nonalignment of striations across the muscle section, and mechanical wave propagation effects. A continuum theory incorporating sarcomere interactions would be very useful in interpreting physiological data.