Final answer:
Knee braces can have detrimental effects on muscle activity and performance by changing muscle activation patterns, reducing sprinting speed, and increasing fatigue.
Step-by-step explanation:
Possible detrimental effects of knee braces include changes in muscle activity during gait, reduction in sprinting speed, and an increase in the onset of fatigue. Therefore, the answer is D. all of the above. Knee braces may alter muscle activation patterns during movement, which can lead to a decrease in muscle efficiency and athletic performance. Additionally, wearing knee braces can increase the fatigue experienced by the muscles due to the added support and restriction of movement.