BIOMECHANICS & ANALYTICS

“Dimensions of the court and physical laws determine stroke production, not any coach’s opinion or any unique theory.” - Vic Branden

Pic credits: Tennis Warrior

Biomechanics is the study of Human Motion. Biomechanics is the sport science field that applies the laws of mechanics and physics to human performance.
Biomechanics is all about finding a better way to hit the ball - there is no right way or wrong way. Biomechanics helps prevent misuse & overuse.
Tennis Development is a natural consequence of Biomechanics. It Involves efficiency of movement and effectiveness in performing at the highest level.
To understand how players develop coordinated skills, control, consistency, placement and power, it is important to consider the idea of a linked system of body segments.
Primary Biomechanics:
  • 1. Analyze
  • 2. Optimize
  • 3. Maximize Performance
  • 4. Minimize Injuries
Components of Biomechanics:
  • 1. Kinetics
  • 2. Kinematics
  • 3. Levers
  • 4. Equilibrium

Two Main Goals of Biomechanics

1. Performance Enhancement:
  • A. Technique Improvement
  • B. Training Improvement
2. Injury Prevention & Rehabilitation:
  • A. Techniques to reduce Injury
  • B. Adaptive training to reduce Injury

Directions to record your video

  1. Record your video in 4 different Angles.
  2. Front View - 45 degrees angle facing the player.
  3. Side View (beside the player) & facing the player.
  4. Back view (behind the player).
  5. Side back view
  6. Make sure the camera is still and doesn’t move during the recording.

Tennis Strokes

“Float like a butterfly, sting like a bee.” – Muhammad Ali

Serve
Return of serve

Forehand
Backhand
Underspin Backhand

Approach Shot
Drive volley


Volley
Overhead smash

Dropshot
Lob

Tweener

Sample Study

It does not matter how great the stroke is if the player is not in the right place at the right time. Video analysis is becoming increasingly useful for identifying, analyzing and correcting inefficiencies with player's sporting technique. Coaches and athletes are using the medium more and more to measure and correct technique.

Every checkpoint in a Tennis stroke is path dependent, which is a scientific way of saying it doesn’t matter that the body/ racquet got there, but how it got there makes a difference. It is also necessary to have a good understanding of the application of maths & physics to sport, as physical principles such as motion, resistance, momentum and friction play a part in most sporting events.

Progression of learning a Tennis stroke:

Forehand :
1. Shadow Practice
2. Drophit
3. Hitting of a cone
4. Tosser-Hitter
5. Wall Practice
6. Rally

Breaking down a Tennis Serve:

1. Ready Position.
2. Unit Turn.
3. Backswing.
4. Trophy Pose.
5. Racquet lag.
6. Forward Swing.
7. Follow Through.
8. Forward Step.

Serve study report:

  • 1. The serve is the most strenuous stroke in tennis and deserves critical analysis.
  • 2. Art is always in the Start.
  • 3. Arms should always be loose & Relaxed.
  • 4. Serve is basically “Throwing” action which is a combination of rotational and linear motion of the body.
  • 5. Grip determines the angle of the racquet face; The racquet face determines the angle of the square path.
  • 6. Grip: Reference points – Base Knuckle and heel of the hand.
  • 7. Continental Grip: Base knuckle & heel of hand to be placed on Bevel 2 of the Racquet Grip.

Pic Credits: Align Body Clinic

“To hear is to forget it, To write is to remember it, To do it is to understand it.” - Confucius

Points to remember:

  1. Knowledge is king.
  2. There is nothing right or nothing wrong. It’s about the efficiency and probability that we base this study on. What one might feel right might be wrong to the other person. Perception is different for each person.
  3. Main goal of this analysis is to achieve efficiency to the maximum possible level.

    Ex: You can drive a car with fully inflated tires or half inflated tires too. But fully inflated tires give more efficiency and mileage for the vehicle and its parts and tires.

  4. Efficient Skills come from knowledge and repititon (practice).
  5. Every position in a tennis stroke is path-dependent. Which is a scientific way of saying it doesn’t just matter that the body/racquet got there, but how it got there makes a difference.
  6. Long, smooth acceleration tends to be better controlled than short, violent acceleration.
  7. Rule #1 – Keep the ball inside the court, style and speed come only if you obey Rule #1.
  8. Mistake management is very essential for success.
  9. Insecurities come from lack of fully understanding.
  10. When you are prepared, you don’t panic.
  11. Try to listen to the sound of the ball.
  12. Present a good body language on the court.

KINETIC CHAIN:

  • KINETIC CHAIN is a linked system. It works in a very systematic way with the legs interacting with the ground. The legs take the force and transfer the force to the hips, from the hips force is transferred to the trunk, from the trunk to the arm, and from the arm to the racket. The summation of this kinetic chain adds up to racket velocity and control. It is important to understand this kinetic chain so that we can better recognize errors or inefficient movement.
  • One aspect of inefficient movement is when one of the body parts is left out or when the kinetic chain is broken. This means that subsequent body parts must constitute to work harder.
    For example: When the two handed backhand is hit with no trunk rotation the arms must swing harder, increasing the chance of an error.

  • A second form of inefficient stroke production occurs when all of the body parts are used but not employed correctly.
    For example: When hitting the serve the legs may not be utilized completely, resulting in the hips and trunk working harder to create arm and racket speed.
  • A final aspect of inefficiency takes place when the kinetic chain is not properly synchronized.
    For example: Some players have a hitch in their service motion. It throws the timing of the body’s kinetic chain out of synch, forcing the arm to swing with excessive action.
  • There is no perfect way to stroke the ball, but there is one time when the stroke must be perfect -IMPACT. Regardless of grip type, backswing or follow-through, impact must be exact for a player to hit a specific shot. This involves having control over the racket head and swinging the racket with optimal speed.
  • Following is a biomechanical look at the four basic strokes: Forehand, backhand, serve and volley, as well as footwork.







Forehand

Shoulder speed has been shown to contribute 25% of racket speed. The rotation of upper arm, forearm, and hand, account for the remaining 75% of racket speed at impact. Research indicates that the segmental contributions are influenced by grip type and ball level. Forward movement of the upper arm is a key feature of forehand mechanics, producing 30% of the racket speed. The hand plays an integral role in generating racket speed. The follow-through is across the line of the body and a recovery step brings the player into the ready position.

Backhand

Like the forehand, racket speed at impact is derived from a sequencing of trunk and shoulder rotation as well as arm and hand extension. The backhand underspin has an impact point that occurs closer to the front foot and closer to the body. At impact the racket shoulder moves more toward the net than the topspin stroke. The two-handed backhand is a three-segment sequence (hips and trunk / upper arms and hands) as opposed to the five-segment sequence of one handed backhands (hips, trunk, upper arm, forearm and hand). All things being equal, the kinetic chain is virtually the same for both types of backhands and should be observed as such.

Serve

The serve is the most strenuous stroke in tennis and deserves critical analysis.
The toss should be positioned in front and slightly to the left of the front foot, and should be impacted at the top of its flight. The swing to impact involves the lower limb drive, together with trunk rotation that produces the shoulder rotation - this represents 20 percent of the racket speed. The rotations of the upper arm, forearm and hand account for the remaining 80 percent of racket speed. Hand and wrist flexion (Forearm snap/pronation) are the last movements and produce 30% of the total racket speed. Therefore the wrist action is an extremely important aspect of serve mechanics.

Volley

For effective volleys, players need to execute a split step in preparation for both volleys. The backswing requires an increased shoulder rotation on the backhand volley as the racket has to move to the opposite side of the body.

During the forward movement of the racket, the left foot (for Forehand volley) or right foot (for Backhand volley) steps towards the ball. Much of the power in the volleys comes from this step. The upper limb movements are responsible for the majority of racket speed at impact. Lastly, the wrist must be firm (fixed) at impact. The follow-through decelerates immediately after impact as the racket resumes its ready position.

A similar kinetic chain of body segments accompanies the remaining Tennis strokes. Effective analysis of this kinetic chain is an essential ingredient in developing technique in stroke production and in determining the possible cause of an injury.

Footwork

Footwork, or movement, is another important biomechanical attribute. A player’s positioning, and how he or she uses the ground is crucial for stroke production. It does not matter how great the stroke is if the player is not in the right place at the right time. From the sports medicine point of view, when a player is out of position, it is difficult to use the body properly in generating force to hit the ball which means that the upper arm must work harder than it should.

Most importantly, a split step must occur just as the opponent is starting the forward swing. This movement primes the body in readiness for an explosive move in any direction. In a split step the feet should be shoulder width apart, with legs flexed, the upper body leaning slightly forward. This ground action force is necessary to decelerate the body from one direction and accelerate the body in another direction.

Conclusion - There should be a coordinated effort between the legs and the upper body.

“Start where you are, use what you have, do what you can.  – Arthur Ashe”

loog

Professional Tennis Lessons

Important Links
Join Our Community
Follow Us

Address: Meadows Sports Village, Chittivalasa, Bheemunipatnam, Visakhapatnam - 531162

The Tennis Theory © All Rights Reserved