As its name suggests, the butterfly groin stretch targets the groin muscles, which are located within your inner thighs, crossing the inside of your hip joints. These muscles facilitate hip adduction, which occurs when you move your legs together from a spread-out position. Performing any variation of the stretch on a regular basis helps increase your hip-joint flexibility, allowing you to spread your legs apart and bring them back together freely and potentially preventing groin-pull injuries, which are common among athletes.
Applied Anatomy
The inner-thigh muscles that produce hip adduction include the adductor brevis, adductor longus, adductor magnus and gracilis muscles. The first three of these muscles attach to the pubis, which is a bone on the bottom, inside portion of your pelvis, on top and to the inside of the thigh bone on the bottom. The gracilis also attaches to the pubis on top, but to the tibia bone of your lower leg instead of the thigh bone on the bottom. All of these muscles lengthen when you perform the butterfly groin stretch, which involves abducting your hips, or spreading your legs apart, as far as is comfortable.
Static-stretch Variation
Static stretches involve stretching a muscle until you feel gentle tension and then holding the stretch for a specific period of time. Sit upright with your legs in front of you to prepare for the static variation of the butterfly groin stretch. Flex your knees and spread them apart, bringing the bottoms of your feet together in front of your torso with the outsides of your feet resting on the floor. Lean forward slightly and grasp around your feet, placing your elbows on the insides of your knees, then press downward until you feel a light stretch through your inner thighs. Hold this position for 10 to 30 seconds, then relax. Repeat the stretch multiple times.
Dynamic-stretch Variation
The dynamic butterfly groin stretch involves lengthening and shortening the groin muscles repeatedly instead of holding them in a stretched position. This variation mimics athletic movements, such as playing defense in basketball, more closely than static stretches and thus may be more appropriate than the static variation, especially if you're an athlete. Perform the exercise just like the static version, but hold the stretch for only a second, then bring your knees closer together. Repeat this process at least 10 times, progressively increasing the range of motion with each repetition.
The PNF Stretch Variation
The proprioceptive neuromuscular facilitation, or PNF, variation of the butterfly groin stretch begins just like the static exercise. Perform the static stretch for 10 seconds, then contract your inner-thigh muscles for about five seconds while maintaining pressure with your elbows. Finally, relax your muscles once again, deepening the stretch slightly, and hold for 30 seconds. Repeat this process several times. You can also have a partner press downward on the inside of your knees, if desired.
References
- "NSCA's Essentials of Personal Training"; Roger Earle and Thomas Baechle; 2004
- ExRx.net: Seated Groin Stretch
- "Basic Biomechanics"; Susan Hall; 2007
- "Full-Body Flexibility"; Jay Blahnik; 2004
