Sidelying hip abduction with a velcro-stabilized 5 lb ankle weight is best described as which type of strength training?

• A. Isotonic
• B. Isometric
• C. Eccentric
• D. Concentric

Answer: (A)

Isotonic training involves moving a limb through a range of motion against a constant external load. In sidelying hip abduction with a 5 lb ankle weight, the leg moves away from the body while being resisted by the weight, so the hip abductors shorten and lengthen as you go through the lift and, if you control the descent, also lengthen while under load. The key idea is movement with a steady resistance, not just holding a position. The upward portion is a concentric contraction (muscle shortens to produce the movement), and the lowering portion would be eccentric (muscle lengthens under tension); both are part of an isotonic activity. Isometric would involve no joint movement (holding still), which isn’t the case here.