Purpose of this Biomechanical Analysis

This blog will show a biomechanical analysis of three swimming positions along with individual steps and instructions for performing each position. The three positions demonstrated in this blog are freestyle, backstroke and breaststroke. It is important to take the following instructions for proper execution of movements. Failure to properly conduct the movements can lead to many unwanted injuries.

All the following swimming positions should begin with the swimmer in a prone or supine position. Most of the movements for these strokes involve the following joints: glenohumeral joint, ulnohumeral joint and radioulnar joint. Along with these joints the lower body involves the following joints: iliofemoral joint, tibiofemoral joint, subtalar joint and talocrural joint. Other joints might also be used but the ones displayed play bigger roles in the swimming strokes for this blog.

During swimming a lot of the body's musculature is used. Some of the most important musculature used is displayed below.

Upper Body Musculature Includes: Pectoralis Major, Brachialis, Deltoid, and Rotator Cuff Muscles (Supraspinatus, Infraspinatus, Teres Minor and Subscapularis).

Core Musculature Includes: The abdominals which are comprised of the Rectus Abdominis, Transverse Abdominis, External and Internal Obliques.

Leg Musculature Includes: TFL, Quadricep Muscles, Hamstrings, Tibialis Anterior, Gastrocnemius and Soleus.

Freestyle:

Novice and Expert Videos-

The following videos show an expert and a novice executing the freestyle swimming position.

Due to camera angles, poor equipment and excessive instability of hand recorded videos the following animation is provided below. This animation is perhaps the best representation for the proper execution of the freestyle stroke due to its stability and ability to provide all aspects of movement clearly.

Phases of Freestyle Swimming

Upper Body-

1. Entry Phase

During the entry phase you want to begin by flexing the elbow, the elbow should be superior to the hand during this phase. The hand should be anterior to the shoulder with the fingers adducted completely. The fingertips should enter first with the thumb down and arm internally rotated. The arm should slide anteriorly and slightly inferior until it reaches maximum extension in front of you.

2. Catch Phase

The catch phase begins as soon as the arm is fully extended during the entry phase. During the catch phase the elbow has to flex and the shoulder must internally rotate in order for the fingers to point down towards the bottom of the pool. At this point the hand is used to begin propelling the body forward. Abducting the fingers does not allow for proper "catching" of the water.

3. Pull Phase

The pull phase begins usually half way through the catch phase and from this phase the swimmer can gain a lot of speed. During the pull the hand, forearm and arm pull the water caught during the catch phrase and move posteriorly past the shoulder. During this phase the elbow remain flexed until it passes the shoulder and then it moves onto the next phase.

4. Follow-through Phase

The follow through phase begins as soon as the flexed elbow passes the shoulder during the pull phase. Once the elbow moves posteriorly past the shoulder, the arm elbow begins to extend until it it parallel to the thigh. At the end of this phase the arm should be fully extended to the side of the swimmer

5. Recovery Phase

The recovery phase begins as soon as the arm is completely extended to the swimmers side. The swimmer must hyperextend the shoulder at the glenohumeral joint and slightly externally rotate in order to allow arm to position itself to exit the water. Once the arm externally rotates you want to let momentum guide your arm out of the water where you will flex at the elbow again to begin the entry phase.

Lower Body-

Coordination between upper body and lower body is key to successful execution of all swimming strokes. I have separated upper body and lower body to explain the steps within the stroke for the lower body. *Do not execute upper body and lower body movements at different times, if you observe the videos provided you can see how simultaneously the upper and lower body work together for fluid movement* The low body moves mostly using the main joints of the ankle which include the subtalar joint and talocrural joint.

1. Hip Movement

Many swimmers flex their tibio-femoral joint along the too much while kicking this is considered kicking from the knee. This creates large amounts of drag and causes swimmer's legs to sink low in the water. Instead of kicking from the knee you should kick from the hip with a relatively extended leg. You should keep your legs extended and move them simultaneously up and down. It is best not to think about flexing your knee at all, instead think about kicking from the hip at the iliofemoral joint with an extended leg and a very slight flexion of the knee will happen naturally.

2. Foot Movement

When you swim you should always have your ankle plantar flexed. Not pointing your toes down and keeping the ankle in dorsi-flexion will push water anteriorly when you kick, slowing your velocity dramatically.

Common Mistakes:

Dropping the elbow, abducting the hands allowing water to seep through, not moving the legs, excessive dorsiflexion of the ankle, not properly breathing.

Cue:

Always keep the elbows high and keep coordination between upper and lower body.

Catch-Up Drill:

This drill is good for freestyle because it emphasizes a power feeling in the last third of the stroke.

• With both arms extended above the head, pull with one hand, recover to the beginning (both arm

extended forward) and touch the other hand. Focus on locking your elbow straight when you

extend your arm to touch the other hand.

• Repeat the motion with the other hand.

Backstroke:

Novice and Expert Videos-

The following videos show an expert and a novice executing the backstroke swimming position.

Due to camera angles, poor equipment and excessive instability of hand recorded videos the following animation is provided below. This animation is perhaps the best representation for the proper execution of the freestyle stroke due to its stability and ability to provide all aspects of movement clearly.

Phases of Backstroke Swimming

Upper Body-

1. Initial Position Phase

In order to proper execution of the backstroke, the swimmer must begin in a supine position. For the initial position the glenohumeral joint of the shoulder must be flex and slightly externally rotate with the elbow completely extended. At this point the fifth phalange should be inferior to the first digit and in contact with the water.

2. Catch Phase

Catch phase (first part of the power phase). The arm and hand enters downward starting with the fifth metatarsal first then flexing slightly at the elbow catching the water while moving anteriorly with the phalanges adducted.

3. Mid Pull Phase

Once the catch is made the flexed elbow should move anteriorly pulling the body through the water and extending simultaneously to end up at the side of the body.

4. Finish Phase

During the finish phase, the forearm should pronate and begin to come out of the water with the fifth metatarsal first ready to continue to the recovery phase.

5. Recovery Phase

The recovery phase consists of the final semi circle returning the hand to it's original position superior to the head.

Lower Body-

Coordination between upper body and lower body is key to successful execution of all swimming strokes. I have separated upper body and lower body to explain the steps within the stroke for the lower body. *Do not execute upper body and lower body movements at different times, if you observe the videos provided you can see how simultaneously the upper and lower body work together for fluid movement* The low body moves mostly using the main joints of the ankle which include the subtalar joint and talocrural joint.

1. Hip Movement

Many swimmers flex their tibio-femoral joint along the too much while kicking this is considered kicking from the knee. This creates large amounts of drag and causes swimmer's legs to sink low in the water. Instead of kicking from the knee you should kick from the hip with a relatively extended leg. You should keep your legs extended and move them simultaneously up and down. It is best not to think about flexingyour knee at all, instead think about kicking from the hip at the iliofemoral joint with an extended leg and a very slight flexion of the knee will happen naturally.

2. Foot Movement

When you swim you should always have your ankle plantar flexed. Not pointing your toes down and keeping the ankle in dorsi-flexion will push water anteriorly when you kick, slowing your velocity dramatically.

* Rotation of the entire body when swimming backstroke it essential*

Common Mistakes:

Unnecessary movement of the head, slap back of hand to water, failing to flex the elbow and not rotating body.

Cue:

Look up at ceiling, flex elbow and rotate body.

One-Arm Backstroke Drill

This drill focuses on body roll, rotating shoulders and hips together, and developing strength with a deep pull.

-Hold the right arm at your side next to your body and swim 25 using just the left arm. Focus on rolling to your left during the pull and back to the right during the recovery.

-Switch arms (left arm at your side and pull with the right arm) and swim back. Focus on rolling to your right during the pull and back to the left during the recovery.