What best indicates low back health during fitness assessments?

The curl-up test is an effective measure of low back health during fitness assessments because it evaluates the strength and endurance of the abdominal muscles, which play a significant role in supporting the spine and maintaining proper posture. Strong abdominal muscles contribute to a stable core, which is crucial for protecting the lower back from injury during various physical activities and everyday movements. Assessing performance in this test provides insight into an individual's core strength and endurance, both of which are key factors in promoting overall back health and preventing disorders related to the lumbar region.

Other tests like the vertical jump test, endurance run test, and sit-up test may focus on different aspects of fitness such as explosive power, cardiovascular endurance, or abdominal muscular strength, but do not directly target the influence of core stability on low back health in the same way that the curl-up test does. Thus, the curl-up test is the most relevant indicator of low back health.