Why is lumbar paraspinal NMES considered appropriate for older adults?

Why is lumbar paraspinal NMES considered appropriate for older adults?

• A. They have a decreased number of type II fibers
• B. They have more type II fibers
• C. They have less muscle mass
• D. They respond poorly to high frequency

Answer: (B)

Electrical stimulation tends to recruit fast-twitch (type II) motor units more readily because their fibers have larger nerve fibers and respond at lower thresholds to the pulsed current. If older adults have a higher proportion of type II fibers, lumbar paraspinal NMES can elicit strong, purposeful contractions in the back muscles with less voluntary effort, which is helpful for improving lumbar stability and function. This makes NMES a practical option for strengthening the paraspinals in older adults, especially when endurance or manual exercise tolerance is limited. The other points — such as simply having less muscle mass or relying on high-frequency responses being poor — don’t explain the targeted effectiveness as clearly. The key idea is that a greater presence of type II fibers means NMES can more effectively activate the muscles that need strengthening.

Electrical stimulation tends to recruit fast-twitch (type II) motor units more readily because their fibers have larger nerve fibers and respond at lower thresholds to the pulsed current. If older adults have a higher proportion of type II fibers, lumbar paraspinal NMES can elicit strong, purposeful contractions in the back muscles with less voluntary effort, which is helpful for improving lumbar stability and function. This makes NMES a practical option for strengthening the paraspinals in older adults, especially when endurance or manual exercise tolerance is limited.

The other points — such as simply having less muscle mass or relying on high-frequency responses being poor — don’t explain the targeted effectiveness as clearly. The key idea is that a greater presence of type II fibers means NMES can more effectively activate the muscles that need strengthening.