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Freestyle stroke: :

The Biomechanics of the Upper E xtremities Freestyle stroke: By: Tiffany Duncan, Allyson Gennteman , Tabitha McMillan, Mark Schindler and Johanna Stivers


3,200 years ago Egyptian soldiers used an over-arm stroke to pursue there enemies across the Orontes River. Local Indian’s on the coast of Brazil swam with an overhand stroke The Australians were the first to adopt and refine the technique. Introduced by Harry Wickham Americans improved on the technique of the kick to increase the speed in the water. History


Stages of the freestyle stroke Planes and Axes Muscles involved Movements Joints involved Kinematics

Stages of the freestyle stroke:

Stages of the freestyle stroke A.) Elbow-Lift B.) Recovery C.) Catch D.)Pull

Planes of the Freestyle Stroke:

Planes of the Freestyle Stroke Fontal ( anterioposterior axis) Abduction Arm Elevation & Depression Shoulder Sagittal ( mediolateral axis) Flexion & Extension Elbow & wrist Slight Flexion & Extension F ingers Extension & Hyperextension Shoulder Transverse (longitudinal axis) Horizontal Abduction & Adduction Shoulder Rotation Trunk &shoulder Pronation & Supination Forearm

Anterior muscles involved:

Anterior muscles involved Pectoralis Major Serratus Anterior Subscapularis Biceps Brachii Poectoralis Minor Coracobrachialis A.) Deep B.) Superficial

Posterior Muscles involved:

Posterior Muscles involved Latissimus d orsi Trapezius D eltoid Rhomboid major Supraspinatus Levator scapulae T riceps Infraspinatus Teres Minor Teres Major Rhomboid Minor

Anterior forearm :

Anterior forearm Brachioradialis Flexor Carpi Radialis Pronator Teres Palmaris Longus Flexor Capri Ulnaris Flexor Pollicis Brevis Pronator Quadratus Brachialis Flexor Digitorum Superficialis Supinator Flexor Digitorum Profundus Flexor Pollicis Longus Flexor Digiti Minimi Brevis A.) Superficial B.) Deep C.) Deeper

Posterior Forearm:

Posterior Forearm Flexor Carpi Ulnaris Extensor Carpi Ulnaris Extensor Digiti Minimi Brachioradialis Extensor Carpi Radialis Longus Aconeus Extensor Carpi Radialis Brevis Extensor Digitorum Extensor Pollicis Longus Extensor Pollicis Brevis Extensor Indicis Abductor Pollicis Longus A.) Superficial B.) Deep

Movements Of the Freestyle stroke:

Movements Of the Freestyle stroke Movement Muscles Phases Abduction of Arm Deltoid (middle) Supraspinatus Biceps Brachii (long head/assists) Recovery Flexion of Elbow Biceps Brachii Brachialis Brachioradialis Pronator Teres (assists) Elbow-lift, & Pull Extension of Elbow Triceps Brachii Aconeus Recovery Pronation of Forearm Brachioradialis Pronator teres Pronator quadratus Catch Supination of Forearm Brachioradialis Biceps brachii Supinator Recovery Horizontal Abduction Trapezius Rhomboid major & minor Biceps brachii Coracobrachialis Pectoralis major Deltoid Recovery Catch


Movement Muscles Phases Flexion of Wrist Flexor capri radialis Flexor capri ulnaris Palmaris longus Flexor digitorum superficialis & flexor digitorum profundus assist Elbow-lift Extension of Wrist Extensor capri radialis longus , Extensor capri radialis brevis , Extensor capri ulnaris Recovery Flexion of Fingers Flexor digitorum superficialis Flexor digitorum Flexor pollicis longus Lumbricals Palmar interossei Dorsal interossei Catch & Elbow-lift Extension of Fingers Extensor digitorum Extensor digiti minimi Extensor pollicis longus Extensor indicis Lumbricals Palmar interossei Dorsal interossei Recovery Movements


Movements Muscles Phase Elevation of Shoulder Levator scapulae Rhomboid major & minor Recovery Depression of Shoulder Trapezius Subscapularis Serratus anterior Latissimus dorsi Catch Medial Rotation of Shoulder Subscapularis Pectoralis major Latissimus dorsi Teres Major (assists) Biceps brachii Deltoid Recovery Lateral Rotation of Shoulder Infraspinatus Teres minor Deltoid Supraspinatus (assists) Catch Extension/Hyperextension of shoulder Teres minor Teres major Latissimus dorsi Pectoralis Major Elbow-lift & Pull movements


Shoulder Gleno -humeral Elbow Humeroulnar Humeroradial Proximal Radioulnar Wrist Radiocarpal Mid-carpal Intercarpal Carpometacarpal Fingers Metacarpophalangeal Proximal & distal interphalangeal JointS


Joints A.) Shoulder B.) Elbow C.) Wrist D.) Hand

Exercises for Improvement:

Exercises for Improvement A.) Lat Pull Down B.) Bicycle Crunches C.) Chest Press D.) Back Extensions


Newton’s Laws of Physics Forces Drag Resistance Viscosity Buoyancy Torque Kinetics

Newton’s laws of physics- applies to the freestyle swim stroke:

Newton’s laws of physics- applies to the freestyle swim stroke 1 st 2 nd 3 rd If one were to stop stroking, the body would still glide in the direction that one was originally moving. Pulling the arm through the water causes acceleration. The arm is putting pressure on the water and the water is putting pressure back on the arm. As the arm puts force on the water the water puts a force inversely proportional to the body's mass.


During the action of stroking, the arm goes through the water causing the body to accelerate forward. As the palm catches the water and puts force on the water, the water puts force on the palm causing the body to accelerate forward. Forces


Drag is a resistance force that slows down normal human movement and is due to these three factors: Frontal resistance the body rides too low in the water, creating a large surface area that causes more resistance Skin friction the kinetic friction of the swimmer’s skin and suit with the water Eddy resistance caused by poor stroke technique and as a swimmer’s hand enters the water a bound vortex forms around the swimmer’s hand and arm, in the general swimming technique this vortex causes the swimmer to pull water and air bubbles along with them causing more resistance. Forces


Viscosity is a frictional force between different layers of water as they move past one another. Pressure drag is a pressure differential that arises between the front and the rear of the swimmer. Wave drag is described as swimming near the water surface, water tends to pile up in front and forms hollows behind the swimmer, creating a wave system. Forces


Buoyancy is best described by Archimedes’ principle: a body fully or partially encapsulated by fluid is buoyed up by a force equal to the weight of the fluid that is displaced by the body . Buoyancy


Torque 1 2 3 4 The Catch : Is an indirect contributor to creating torque, but without it, the transfer of power from the trunk to the arms would fade. The Pull : creates acceleration under the body, and contributes to the rolling of the trunk which is where the main torque is created. Recovery : Directly contributes to creating torque. Causes the body to change direction into a body roll, and creates movement in the opposite direction. Attack Angle – A 30 degree attack angle creates the smallest amount of drag. Less drag will correlate with less power being used (torque).


Torque The Left and Right are the Breathing Laterality. The results were all taken as averages. The side the swimmers chose to breathe from was the side that generated the least amount of torque More torque is generated on the opposite side due to the larger amount of body roll when taking a breath. Explanation

Tools for analysis:

Visual- A coach visually watching his/her swimmers and making corrections on the spot. Video-Motion Analysis: underwater recordings are analyzed using computer software to measure angles and look for ways to improve performance Inertial Systems- a full body suit which can analyze the strengths and weakness of elite-level swimmers. Laboratory of Movement Analysis and Measurement Tools for analysis


Activity Trial 1 Trial 2 Trial 3 Average Freestyle swim 961 uV 300uV Shoulder s hrug 1430uV 1296uV 1643uV 1456uV Electromyography Summary: Swimming average was lower than expected. The shoulder shrug focused more on the Trapezius muscle. A 45lb bar along with two external forces pushing down caused a much greater resistance. The swimming motion had no resistance other than gravity. Test was inconclusive due to lack of water resistance.

Upper Extremity Swimming injuries:

Upper Extremity Swimming injuries Elbow Shoulder

Shoulder injuries:

Known as shoulder impingement syndrome or swimmers shoulder Effects 70% of competitive swimmers If left untreated than can result into a rotator cuff tear Shoulder injuries

Causes of Shoulder injuries:

Continuous motion of the shoulder eventually cause the tendons in the rotator cuff to become impinged while they pass through the subacromial space (narrow bony space). Tendons and bursa become irritated and inflamed which cause them to thicken and become much harder to pass through the small space. Muscles then start to weaken and the rotator cuff tendons may begin to tear. Causes of Shoulder injuries

Prevention of Swimmer’s Shoulder:

Prevent Injury Do not swim when sick, tired, or overheated Always warm up and focus on technique Substitute swimming with weight training/exercise Stretching Bilateral breathing Prevent Re-Injury Take time off Ice Take anti-inflammatory medication Physical therapy Continue weight training but with no weights and heavy lifting Prevention of Swimmer’s Shoulder

Elbow injury:

Less common in competitive swimmers Most likely to be on the medial side (inside) of the elbow. Causes the “pull” part of the stroke to be extremely painful. Elbow injury

Cause and Prevention of elbow injuries:

Cause Many strokes with poor technique Prevention Rest Stretching – ex: biceps stretch and elbow extension stretch. Cause and Prevention of elbow injuries

Souces :

Barbosa, T. M., Marinho , D. A., Costa, M. J., & Silva, A. J. (2011). Biomechanics of competitive swimming strokes. doi : Dennis, A. ( n.d. ). Torque technique . Retrieved from " Everyday Health . HealthDay News, 23 Jul 2011. Web. 1 Mar 2012. <;. Hall Susan, J. Basic biomechanics . 5. New York NY: McGraw-Hill, 2007. . "Common Swimming Injuries Often Avoidable. Magnuson, Dale. "A Biomechanical Analysis." . N.p ., 07 Jul 1998. Web. 1 Mar 2012. <>. Souces


Moynes , Diane R., Jacquelin Perry, DAniel J. Antonelli , and Frank W. Jobe . "Electromyography and Motion Analysis of the Upper Extremities in Sports." Journal of the American Physical Therapy Association . 66. (1986): 1905-1911. Web. 1 Mar. 2012. < html>. Tourny-Chollet , C., Seifert, L., & Chollet , D. (2009). Effect of force symmetry on coordination in crawl. Int J Sports Med , 30 (3), 182-187. doi : 10.1055/s-0028-1104581 Toussaint, Hubb M., A. Peter Hollander, Coen van denBerg , and Andrei Vorontsov . "Biomechanics of Swimming." Exercise and sports Science . (2000): 639-660. Web. 1 Mar. 2012. <>. "Wading Through Swimming Injuries and Prevention." Cleveland Clinic . N.p ., n.d. Web. 1 Mar 2012. <;. sources

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