Freestyle swimming, also known as the front crawl stroke, involves movements that work muscles throughout your midsection, upper and lower body. Strengthening individual muscle groups can help improve your form and efficiency of the freestyle swimming stoke. . Different muscle groups contribute to particular elements of the freestyle stroke, and you can avoid overuse injuries by strengthening those muscles. Freestyle swimming primarily relies on muscles in your torso, thighs and lower legs.
Shoulder Blade Rotation
Your shoulder blades rotate upward as you reach forward and prepare for the pulling and pushing portion of the freestyle stroke. Reaching as far forward as possible maximizes the efficiency of the stroke. Reaching farther forward helps you catch the water at the front of the stroke, which allows you to travel further with each stroke. The primary muscles responsible for rotating your shoulder blades upward are the middle and lower fibers of the trapezius in the middle of your back and the serratus muscle around the top of your rib cage.
Freestyle swimming works the muscles that extend your shoulders as your arms move down and back during the pushing and pulling portion of each stroke. The latissimus dorsi extend your shoulder while moving your arms down and up through the water. The pectoral muscles are particularly active during the pulling portion of the stroke while your shoulders rotate more internally. The back deltoids hyper-extend your shoulder as you complete the pushing portion of each stroke.
The kick for freestyle swimming is known as the flutter kick, which requires alternately separating your legs and drawing them together. The legs produce propelling force as you do this. Muscles that generate force include the gluteus maximus and hip flexors, which extend and flex your hips, respectively. The power of your kick also depends on the forward range of motion of your foot. You can generate more power and swim faster if your foot bends more forward while kicking. Your soleus and gastrocnemius are primarily responsible for flexing your foot forward.
Your core muscle group works hard stabilizing your spine during freestyle swimming. The core also stabilizes your hip and upper-body movements during the freestyle. You can more effectively maintain a streamlined form with stronger core muscles. Stronger core muscles enhance the overall efficiency of your stroke by improving energy transference between your upper and lower body, which helps your body work as a single unit. The core includes your inner and outer abdominal, lower back and hip muscles.
- Alexandria Masters Swimming: The Flutter Kick - One of Swimming's Mysteries; Marty Hull; 1997
- ExRx: Hip Articulations
- ExRx: Ankle Articulations
- ExRx: Shoulder Articulations
- ExRx: Latissimus Dorsi
- ExRx: Pectoralis Major (Sternal Head)
- ExRx: Deltoid (Posterior)
- Swim Smooth: What is Body Roll / Rotation?; 2009
- ExRx: Scapula & Clavicle Articulations
- Swim Smooth; Your Core and Posture in Swimming; 2009
- Bodybuilding.com; Core Strength Training – The Key to Optimum Sport Performance; Jason Morgan