Physical Therapy Assistant Practice Exam

What effect does hypokalemia have on muscle function during exercise?

1. Increased muscle strength

2. Decreased muscle cramping

3. Increased muscle cramping

4. Improved endurance

The correct answer is: Increased muscle cramping

Hypokalemia, which is characterized by low potassium levels in the blood, has a significant impact on muscle function during exercise, particularly by increasing muscle cramping. Potassium is a crucial electrolyte that plays a vital role in muscle contraction and the transmission of electrical impulses within the muscles and nerves. When potassium levels drop, muscle cells can become less responsive, leading to alterations in muscle membrane potential and abnormal excitability. As the muscle fibers attempt to contract during exercise with insufficient potassium, they may become overly sensitive, leading to involuntary contractions or cramps. This can compromise the muscle's ability to function effectively, contributing to discomfort and reduced exercise performance. Thus, hypokalemia is directly linked to an increase in muscle cramping during physical activity, which is why this option accurately reflects the physiological consequences of low potassium levels on muscle function.