内劲是人体以意念与内气为引导，使人体的肌肉、经络、骨骼内外上下高度协调而形成的劲力，也是人体力的高级形式，在散打中要求运用到这种体内劲力。( The interior strength is the force formed by the high cooperation of muscle, main and collateral channels and skeleton under the guidance of ideas and internal vital energy. It is also the advanced form in the body and required in free combat.)