Which description is most characteristic of osteoarthritis (OA) when compared to rheumatoid arthritis (RA)?

Choice A reason: Duchenne muscular dystrophy (DMD) is an X-linked recessive disorder. Males (XY) pass their Y chromosome to sons and X to daughters, not the DMD gene. Females (XX) can pass the mutated X to offspring. This statement is incorrect, as males cannot pass the DMD gene to their children.

Choice B reason: DMD primarily affects males, as it is X-linked recessive, and males lack a second X chromosome to mask the mutation. Females are rarely affected, typically as carriers or in rare cases with skewed X-inactivation. This statement is incorrect, as patients are predominantly male, not female.

Choice C reason: Genetic testing identifies DMD gene mutations, confirming diagnosis and guiding treatment, such as corticosteroids to slow muscle degeneration or emerging gene therapies. It informs prognosis, carrier status, and family planning, making it critical for tailoring interventions and counseling families about the disease’s progression and management.

Choice D reason: Not all daughters of a carrier female will be carriers. A carrier mother has a 50% chance of passing the mutated X chromosome to each daughter, making half likely carriers. This statement is incorrect, as it overstates the genetic transmission probability for female offspring.

Choice A reason: Applying heat for 10 minutes every hour is insufficient to relieve back strain and may not prevent recurrent pain. Heat therapy requires 15-20 minutes to relax muscles and improve blood flow effectively. This strategy is not a primary recommendation, as it does not address posture, movement, or ergonomic factors critical for back health.

Choice B reason: Padded shoe insoles absorb shock and support proper foot alignment, reducing stress on the spine during standing or walking. By improving biomechanics, insoles help distribute weight evenly, minimizing strain on the lower back. This is a practical strategy for nurses who stand for long periods, preventing repetitive back pain episodes.

Choice C reason: Sleeping on a soft mattress exacerbates back pain by failing to support spinal alignment, causing excessive curvature. A medium-firm mattress maintains neutral spine position, reducing strain on lumbar muscles and ligaments. This strategy is incorrect, as it does not contribute to minimizing back strain or preventing pain.

Choice D reason: Avoiding prolonged sitting reduces pressure on lumbar discs and prevents muscle stiffness. Prolonged sitting compresses spinal structures, weakening core muscles and increasing strain. Regular movement or standing breaks improve circulation and maintain flexibility, making this a key strategy to prevent recurrent low back pain in workplace settings.

Choice E reason: Sleeping in a side-lying position with flexed knees aligns the spine and reduces lumbar strain. This position, often supported by a pillow between the knees, maintains neutral pelvic alignment, minimizing stress on spinal ligaments and discs. It is an effective strategy for preventing back pain during rest, promoting recovery.