Comprehensive Osteopathic Medical Licensing Examination (COMLEX USA) Practice

What typically limits the end range of motion (ROM) in passive assessments?

1. Muscle fatigue

2. Bone, ligaments, and tendons

3. Nerve compression

4. Joint inflammation

The correct answer is: Bone, ligaments, and tendons

The end range of motion in passive assessments is primarily limited by bone, ligaments, and tendons. These structures physically restrict movement and provide stability to joints, which is crucial for maintaining the integrity of the musculoskeletal system. When assessing passive range of motion, healthcare providers evaluate how far a joint can move without muscular effort. Bone structures create anatomical limits to movement, while ligaments connect bones to one another and help prevent excessive motion that could lead to joint injuries. Tendons, which connect muscles to bones, also contribute to this limit by controlling the movement transfer between the two anatomical structures. Other factors, like muscle fatigue, nerve compression, and joint inflammation, can influence the overall range of motion but do not define the mechanical limits of passive assessment in the same way that the structural components—bones, ligaments, and tendons—do. For instance, muscle fatigue may impact active movement but typically does not affect passive assessments. Nerve compression might alter sensation or innervation of muscles, which can affect active motion performance. Joint inflammation can cause pain and swelling, which may restrict movement but does not inherently alter the fundamental limits imposed by the bones, ligaments, and tendons. Thus, the structural elements play a pivotal role in passively