The kick stays controlled over the supporting leg
The athletic Rock'n'Roll kick consists of preparation with a bent leg, extension, and an active retraction. The thigh lifts during the knee drive, then the lower leg moves forward. Swinging a straight leg up from below is a different movement and makes it harder for you to retract it deliberately. Reach comes from controlled movement, not a jerk of the knee.
For this learning exercise, keep your pelvis as much as possible over your supporting foot. Your supporting knee points in the same direction as your toes and is not locked straight. Start with your foot on the floor, even though athletic Rock'n'Roll later uses a springy, dynamic action in the supporting leg. This lets you first tell whether your balance fails during the kick or the hop.
Actively point the toes of your free leg as you extend it, without tensing them. A higher leg position only makes sense once you can hold it and come out of it without leaning back. This exercise trains control, it is not a flexibility test. The guide to building muscle through dancing explains how exertion and strength training work together. Keep your arms relaxed at first: practicing arms and legs separately reduces extra coordination demands. A complete basic-step sequence is deliberately not included here.




