What Is Functional Loss in VA Disability Claims? 38 CFR 4.40 and 4.45

38 CFR 4.40 establishes that the fundamental purpose of the VA disability rating schedule is to measure functional loss. The regulation defines functional loss as the inability of the body to perform normal working movements with the normal excursion, strength, speed, coordination, and endurance. Even if a joint has full structural stability, impairment in any of these factors represents compensable disability.

38 CFR 4.45 identifies six specific clinical manifestations that must be considered when evaluating joint impairment: (1) less movement than normal, (2) more movement than normal (laxity or abnormal mobility), (3) weakened movement, (4) excess fatigability, (5) incoordination or impaired movement control, and (6) the pain associated with movement, swelling, or deformity.

Under the DeLuca doctrine, when an examiner tests joint range of motion on an ordinary day, they must also estimate how many degrees of movement are lost during an acute flare-up or after repeated daily use. If a veteran can bend their knee 100 degrees in an exam room, but pain and fatigue reduce motion to 70 degrees during flare-ups, the VA must consider the reduced range when determining the rating.

In Correia v. McDonald, the Federal Circuit held that functional loss is not limited to degrees of range of motion. If weakness, lack of endurance, or instability produces functional limitations equivalent to a higher percentage tier, raters are authorized under 38 CFR 4.40 and 4.45 to assign the higher rating even if range of motion alone does not meet that threshold.

Veterans should provide clear evidence of how functional loss affects daily life and employment. Lay statements explaining how pain forces frequent sitting breaks, prevents lifting objects, or causes sudden knee buckling provide essential context. Medical records documenting prescribed knee braces, walking canes, or physical therapy progress notes verify sustained functional limitations.