Mechanics of Sprinting Dr Wendy Truvillion Assistant Principal

Mechanics of Sprinting Dr. Wendy Truvillion Assistant Principal – Athletic Director –Alhambra HS USATF Women’s Track and Field – Vice Chair USATF Junior/HS Focus Group – Co-Chair USATF Women’s Commission – Vice Chair World Athletics Coaches Commission – USA Rep USATF-AZ Vice Chair Adjunct Professor – Grand Canyon University

General Mechanics of Sprinting n Apply to both acceleration and maximal velocity running. n Posture. Good posture with proper alignment of the core of the body is key to efficiency and injury prevention. n n Head Pelvis

General Mechanics of Sprinting n Amplitude of Movement n n n Large ranges of motion should be established in the hips. Knee lift Hip extension n The difference between running and sprinting

General Mechanics of Sprinting n Foot Contact Patterns n n n Under the body’s center of mass. Extension of the hip drives the foot into the track surface. Stabilized ankle in a dorsiflexed position prior to contact, and footstrike occurs on the ball of the foot.

General Mechanics of Sprinting n Upper Body Movements. n n n Relaxed movements of the arms, countering and balancing movements of the lower body. Arms act in reaction to the legs, not vice versa. Faults in arm action are usually the result of faulty leg action.

General Mechanics of Sprinting Relaxation. n n n Sprinting is an activity of aggression BUT the athlete should exhibit a certain degree of relaxation while sprinting. Helps insure the presence of large ranges of motion and good posture throughout.

Talent Demands for the Sprints n n n Good speed, power, and jumping ability are indicators of potential successful sprint candidates. The ability to move the limbs at high speeds can be a precursor to success, provided that the athlete can be taught to express this frequency through large ranges of motion. Often speed capabilities surface only after strength and power abilities are developed over time.

What to Look For…In Good Sprinting! n n Full extension of knee, hip and shoulder (Hip Extension) Front shin angle as it relates to body angle. You want to see a straight line from support leg to head. Recovering shin angle should be less than parallel to ground for first 3 steps Cue – “ push” “bomp”

Sprint Mechanics

Posture

Support Phase • Muscles responsible for stabilizing the body. The quadriceps and gastrocnemius are responsible for arresting the body during the stance phase of the max speed. • A goal is to decrease ground contact time during this phase. Athlete must contact the ground with the foot in front of their center of mass. “Underneath you” • Athletes who can produce equal relative “negative” foot speed in relation to how fast they are running, decrease the braking forces at contact.

Recovery Phase • The recovery is dominated by hip flex action of the free leg. The hip flexion at maximal sprint technique is controlled by the rectus abdominal, iliopsoas, and rectus femoris. The major muscles involved in max speed. • Of all the performance variables upper leg rotational speed is the most critical in sprint performance. Frequency! This speed is critical in recovering the leg after takeoff and producing the beneficial “high knee” position. (Ralph Mann)

Take Off • The prime movers of the Take -off in max speed technique are the erector spinae, hamstrings and gastrocnemius. • Full extension at take off to get the most out of the ground has been shown NOT to increase performance times. The small increase in force is not worth the decrease in stride frequency. • The key to high knee recovery is to limit the leg extension action after take off. (Ralph Mann) • Analogy of riding a skate board. Tap Tap

Full Extension/Flight Phase • The key to high level sprint performance is emphasizing “FRONT SIDE” Mechanics and minimizing “Back Side” Mechanics. • Muscles responsible during full extension of max speed: Gluteus Maximus, Rectus Abdominis, Hamstrings, Internal & External Oblique. • Maximize force production at the ankle, knee, and hip. • John Smith describes this phase as “Jumping down the track”. Force production at contact determines stride length.

Phases of Sprint Races n n All sprint races can be divided into three phases: The Drive Phase or Acceleration Phase n n Build momentum so that maximal velocity can be achieved and to enable a stronger finish. Many failures in the middle and latter stages of a race can be attributed to a poor drive phase.

Phases of Sprint Races n The Maximal Velocity Phase. n n Top speed is reached and maximal velocity mechanics are achieved. In the 400 meters, this maximal velocity phase may refer to maximal desired velocity, not maximal attainable velocity.

Phases of Sprint Races n The Deceleration Phase (speed maintenance) n n When the ability to hold maximal velocity fails. Resist deceleration by continuing to execute proper maximal velocity mechanics as the body loses coordination and fatigues. (speed endurance)

Preliminary Settings and Positions (“On your marks”) n n n n n * Front Pedal is 1 ½ - 2 foot lengths from the line (or. 55 x leg length) * Back Pedal is 2 ½ - 3 foot lengths from the line (or. 42 x leg length from front block) * Hands are shoulder width apart * Index finger and thumb are at the starting line (not touching) * Weight supported on thumb-index finder bridge * Shoulders positioned above the hands to keep weight distributed evenly so as to not overload the quick side * Head (relaxed) in neutral alignment with neck and back * Hips lowered and relaxed * Body weight resting on rear knee * Toes or ball of front in contact with track and firmly against the pedals

n Block Starts

Starting Position - Balance - Posture

“Set” Position n n * Lift hips smoothly above the shoulders (lock-in) * 90 degree angle (front leg – power side) and 120 degree (back leg – quick side) flexion in knee n n n * Shin angle is acute (less than 90 degrees); enhances the ability to apply force to overcome the body’s inertia * “full footed” pressure against block pedals n n * ***NOTE: force application comes from gluts and hamstrings – pre-tension desired to minimize movement time and eliminate a conscious pushing with the real leg at the gun Shoulders above the hands to maximize force application n n **NOTE: angles less than 90 will correlate with lower production. ***NOTE: Do not shift shoulders over the start line, it will adversely affect angles at knee and hip Head in relaxed, neutral alignment with spine * Cue motor response: have athlete focus on their first movement (motor), not the gun (sensory)

Start: Set Back strong and straight Joint angles favorable force application Balance: Front to back, left to right

Movement of the Start (“GO”) n n * Extension of quick side (left) arm to contribute to force production of the power side (right) leg * Rear leg (left) “press” quickly extends, then flex (punch the knee) * Front leg (right) “push” quickly extends completely and forcefully * Extension of both hips (simultaneously) will initiate full extension of both legs to propel C of M forward n n n * * ***NOTE: force must come from gluts and hamstrings to create hip extension Head remains in neutral alignment with spine Arms split powerfully, simultaneously (“shade sun”) Body explodes (displaces) forward and upward Shin angle remains unchanged; thus, contributing to movement of C of M forward * Low foot recovery from pedals; no heel to butt recovery

Recruit: Rear leg-Front leg 1 2

Rear Foot 3

Rear Foot 4

Recruit: Gluts & Hams

Recruit: Gluts, Hams, Quads

Recruit: Quads, Gastroc, Soleus

Shin Angle 1

Shin Angle 2

Shin Angle 3

Shin Angle 4

Shin Angle 5

Shin Angle 6

Shin Angle 7

Shin Angle 8

Departure n n * Athlete is airborne, not walking from the blocks * Each successive stride is the result of increasing velocities and decreasing acceleration values n n n Ankle-hip distance is progressively reduced Shin angles increase Negative foot speed increases * Backside mechanics decrease * Frontside mechanics increase * Pattern of foot placement increases n Ground contact time decreases

n Questions and Answers n. Thank You! n Reference: USATF Coaches Education Level I and II Curriculum Manual, 2006

n Questions and Answers n. Thank You! Reference: USATF Coaches Education Level I and II Curriculum Manual, 2006 -2009 n USATF High Performance Relay Project, 2007 n n