Biomechanics in Badminton

While working with the badminton athletes, the biggest challenge I faced was communicating the cause of the injury to the coaches. The coaches often complained about their lack of understanding of sports science, especially biomechanics of the human body. This article makes the comprehension and application of biomechanics in badminton simpler.

Badminton has a wide range of movement patterns. To simplify, I have divided these basic movement patterns into three categories :

1. Net shots - These shots mostly have a lunge movement pattern.

2. Defensive shots- This is a combination of two movement patterns starting initially with a squat position followed by a side lunge.

3. Attack shots - This movement pattern involves a series of phases leading to a powerful shot.

ANALYSIS OF MOVEMENT PATTERNS

NET SHOTS

Lunging movement is predominant in all net shots. This movement is divided into three phases:

1. Acceleration - The right side hip muscles of a right-handed player initiate this phase. The thigh and the calf muscles work eccentrically (while the muscle lengthens) to assist in this phase.

2. Weight Acceptance - The muscles of both limbs work isotonically (static contraction) to stabilise the lower body and the trunk, so the hands can then move freely.

3. Recovery - The calf muscles initiate this phase with a push-off from the ground, allowing a quick return to the starting position. The thigh and hip muscles assist in the phase.

Incorrect Movement Pattern

1. Landing on the toes first instead of a heel strike.

2. Slow recovery after the second phase.

Consequence of Repeating Mistakes

1. Poor eccentric strength in the muscles leads to tendon inflammation at the knee and ankle joints.

2. Slow on- court movements - If the landing is not correct during the first phase, the subsequent movements will be slow.

DEFENSIVE SHOTS

The original position for any defence shot is a squat followed by a side lunge to defend the shuttle. A squat is an isotonic (static contraction) muscle work of predominantly the thigh (quadriceps) and the hip (gluteus) muscles. The phases of a side lunge are similar to those in the lunge movement pattern used in net shots.

A very crucial aspect of these shots is the core strength. While defending any shuttle, the trunk is in a rotated position. So along with the lower body, the core muscles are also working constantly to stabilise the body in this rotated position.

Research suggests that core muscle stability helps dissipate high-impact loads on the knee and ankle joints, thereby reducing the risk of injury.

Incorrect Movement Pattern

1. Weak kinetic chain during the side lunge (Kinetic chain - Group of body segments interlinked, connecting joints and muscles working together).

Consequence of Repeating Mistakes

1. Muscle pull - Badminton is a sport of repetition of movement patterns. If the lower body lacks enough strength to repeat the correct movements there is a higher chance of injury due to muscles fatigue.

2. Ligament injuries - Ligaments around the knee joint like ACL, MCL and meniscus and ankle joint ligaments are prone to sprain due to poor core muscle strength.

ATTACK SHOTS

The attack shots are divided into two categories forehand and backhand shots.

FOREHAND SHOTS

1. Preparation Phase - All the muscles on the right leg (right side for right-handed players) work eccentrically to prepare the body for the acceleration phase. The upper body is extended to store elastic energy in the muscles whichwill be used later on, for force production.

2. Acceleration Phase - The lower body exhibits a phenomenon known as triple extension, which involves simultaneous extension of the ankle, knee, and hip for force production. This force is then transferred to the shoulder, hand, and wrist. The trunk plays a crucial role as a link between the upper and lower body. This highlights the concept of the kinetic chain, where force generated by the larger muscles is transferred to the smaller ones.

3. Follow-through Phase - While landing the body weight is equally distributed on both the legs. The muscles in the shoulder and upper back work eccentrically to control the produced force, as th is excessive force can easily dislocate the shoulder. This phase is the most crucial for prevention of injuries.

Incorrect Movement Pattern

1. Inappropriate landing - Young players often tend do a lousy landing pattern mostly due to fatigue or lack of knowledge.

2. Inadequate use of kinetic chain- If the smaller muscles are repeatedly used to produce force instead of making use of the larger muscle groups, there is are higher chance of shoulder injury.

Consequence of Repeating Mistakes

1. Ankle ligament injuries - Inappropriate landing pattern leads to ligaments sprains.

2. Shoulder muscle/ tendon injury - Repetitive stress on the shoulder results in tendon or muscle inflammation, most commonly affected are the Rotator Cuff Muscles.

BACKHAND SHOTS

Backhand and forehand attack shots have similar phases. The most crucial aspect of this phase is foot placement during the preparation phase for force generation and trunk rotation during acceleration for force distribution to the upper back, shoulder, and wrist.

Incorrect Movement Pattern

1. Inappropriate/inadequate trunk rotation- The force generated by the large muscles of the lower body should be transferred to the upper body to hit the shuttle forcefully. As previously discussed, in the term “kinetic chain”, the trunk is the link between the upper and the lower body.Thus the timing and the range of trunk rotation play a very important role.

Consequence of Repeating Mistakes

1. Elbow ligament/tendon injuries - inadequate use of the kinetic chain places stress on the elbow ligaments leading to sprains of the elbow ligaments or tendon inflammations.

To summarise, the human body is interlinked with each other. Optimum use of the kinetic chain results in better force production. Repetition of incorrect movement patterns makes an athlete more prone to various injuries. A Physiotherapist and an S&C coach can help an athlete, analyse and correct sports-specific movement patterns.