Most Important Muscles Used in Boxing: Kinetic Chains Explained

published by: Debbie Luna
Last Updated:
October 24, 2022

One might think all it needs is a powerful arm to throw a punch that would knock the opponent cold. However, it is more complicated than that; but a skill that could be learned by understanding the biomechanics involved in boxing.

Boxing exhibits all of the fundamental movement patterns and only a few other sports compare to boxing regarding muscles engaged during activity. Professional boxing has often demonstrated that the most potent punches are synergistic moves of the arm, shoulders, back, abdominals, hips, legs, ankles, and even the toes, that deliver a winning punch.

This article discusses the most important muscles used in boxing, what they do, and the synergistic movements that take advantage of the kinetic energy produced to deliver more speed and power for that knockout punch.

How Boxing has Evolved

Early boxing matches demonstrated less footwork, utilizing less synergistic movements, and did not employ much of the body's momentum to deliver more powerful blows. However, the modern athlete in today's professional boxing has several coaches for different aspects of their training and can utilize advances in biomechanics and strength training.

evolution of boxing

While the greatest boxers of all time hail from this century, it was only possible because much of the techniques they employ are a cumulative result of the learnings of the athletes that came before them. Coaches equipped with knowledge in anatomy, kinesiology, and biomechanics helped these boxers develop and improve certain movements better suited for this specific task.

Boxers today have a much better understanding of their anatomy and the biomechanics involved in maximizing punching force and utilizing the best evasion techniques compared to athletes several decades ago. And this is what makes today's boxers pound-for-pound the better fighter than yesterday's champions.

Evolution of Boxing Techniques and Strategies

Strategies and techniques have changed throughout the history of boxing. Factors such as new rules, coaching style, ring conditions, demands of wealthy patrons, and especially the boxing style of successful athletes heavily influenced the style and techniques employed by other boxers. 

This subjective interpretation of a "winning formula for boxing" has primarily dominated the scene of early boxing history. However, in this day and age, strength training and physical conditioning are done mainly with science-based approaches. 

Advances in kinesiology and biomechanics help develop better evasion and engagement techniques. For example, equipment like electromyography to measure the electrical activity of muscles helped develop more efficient movement patterns for more incredible speed and momentum.

The punch has become one of the most researched movements in sports. It has evolved from a strictly upper-body movement to a full-body kinetic chain delivering more significant momentum at impact.

What are the Most Important Muscles Used in Boxing?

Muscle strength and speed in the upper and lower body are necessary for a boxer's victory; "Hit hard but don't get hit" should be the mantra of every fighter.

The essential muscles in boxing are the ones that help engage the opponent with the most influential force and those that enable the fighter to evade blows easily. These include muscles of the arms, shoulders, abdominals, hips, and legs, among others.

Lower Extremity Muscles

Much of the strength spent during a boxing routine will come from the lower body to maintain balance and movement as the footwork is kept in frequent motion to evade or engage the opponent. However, it also provides much power in delivering that knockout punch by using maximal effort from the feet to the hips.

The most powerful punches start from the foot linking that motion to the leg, hips, shoulder, and finally to the arm. Like any sport, everything begins with footwork and its ability to push the body in any direction and provide balance and coordination.

Flexor Hallucis Longus

The "Pendulum Step" or "Boxing Bounce Footwork," where a boxer rocks the body back and forth using a tiptoeing motion, requires a lot of strength for the muscles involved in ankle plantarflexion.

Flexor Hallucis Longus

The big toe is one of the most critical levers in the lower body, being a vital component of a person's balance. It helps propel the body forward, providing a rigid lever to help push off the ground. When curling the foot up, the muscle that bends the big toes is called Flexor Hallucis Longus (FHL). It also supports the longitudinal arch of the foot.

The FHL is a powerful muscle located on the posterior aspect of the fibula with its tendon passing downward, crossing the rear ankle joint, and entering into the sole to insert at the base of the distal phalanx of the great toe. 

It is responsible for the flexion of the great toe, inversion of the foot, and plantarflexion. Examples of its functions include pushing off the surface when walking, running, and lunging forward.

Flexor Digitorum Longus

The Flexor Digitorum Longus (FDL) is part of the deep muscle group of the posterior compartment of the lower leg. The tendons pass under the foot and cause the toes to grip (digits 2 to 5) and place the foot firmly on the surface, which is vital in maintaining balance. The FDL's functions are plantarflexion, inversion, and flexion of the toes.

Gastrocsoleus Complex

The calf consists of two main muscles — the gastrocnemius and the soleus. The gastrocnemius, together with the soleus, is the primary plantar flexor of the ankle joint. However, the gastrocnemius is the main propellant in walking, running, and lunging. In addition, it allows the body to stand on tiptoes which is a vital function in performing the pendulum step.

Gastrocsoleus Complex

All these lower leg muscles work together to provide balance and the boxing bounce footwork's tiptoeing motion. Training these muscles with single-leg hops, jump rope, and calf raises is best for better speed, balance, and stability.

Quadriceps and Hamstrings

The quadriceps femoris is comprised of four muscles: rectus femoris and three vastus muscles. The quadriceps' function is to extend the knee, While the rectus femoris (along with the iliacus, psoas major, and sartorius) flexes the hip.

quadricep muscles

The three hamstring muscles are the biceps femoris, semimembranosus, and semitendinosus. These muscles are antagonists to the quadriceps. They all cross the knee and hip joints and act upon them. These muscles are responsible for bending the leg at the knee joint and extending the thigh at the hip joint. 

Together these two muscles, along with the feet and calves, work to help the boxer engage the opponent with added punching power by extending the knee and hip. In addition, these two muscles are also involved in evasion movements employed by the athlete.


Core Muscles

The core muscles help a boxer rotate when executing punches providing rotational power for the force initiated from the ground by the foot. It also accommodates the transition of that kinetic force from the lower body to the upper body. A strong and stable core maximizes the torque used during a punching sequence.

Hip Flexors and Glutes

The hip flexors are located anteriorly on the upper part of the inner thighs and the pelvic region. This group of muscles connects the pelvis, thigh bone, pelvis, and lower spine. Together they bring the knee closer to the chest when contracted.

The gluteal muscle has two main groups: large superficial and deep small muscles. The large muscles are the gluteus maximus, gluteus medius, gluteus minimus, and tensor fasciae latae. They abduct and extend the thigh at the hip joint.

gluteal muscles

The small muscles (inner hip muscles) are the piriformis, gemellus superior, gemellus inferior, obturator externus, obturator internus, and Quadratus Femoris. These muscles are the hip's deep external rotators.

The glutes and hip flexors facilitate the transference of the kinetic energy that starts from the foot and turns it into rotational power that provides maximal force in punching.

Abdominals and Erector Spinae

The abdominal muscles consist of these four muscle groups: external and internal obliques, transversus abdominis, and rectus abdominis.

ab muscle anatomy

The transversus abdominis is the deepest muscle and its main function is to maintain internal abdominal pressure and stabilize the trunk; while the rectus abdominis, commonly referred to as the "six-pack," moves the body from the ribcage to the pelvis. These two muscle groups provide stability and are believed to help absorb blows to a certain degree.

The external obliques on opposite sides of the rectus abdominis are responsible for the trunk's twisting motion when contracted but to the opposite side of whichever muscle is engaged. In comparison, the internal obliques operate opposite to the external oblique muscles.

The erector spinae muscles along the spine are responsible for twisting and bending movements. These muscles also help in providing structural strength to support the body.

erector spinae muscles

This twisting motion provided by the obliques and erector spinae muscles is part of the kinetic chain that gives rotational power to the punch that starts in the hips and effectively transfers that force to the shoulders and arms while adding more momentum.

Upper Extremity Muscles

Going up the kinetic chain, the final muscle groups that transfer the kinetic energy from the foot need to be strong enough to deliver the blow and amply stable to absorb the impact. 

Deltoids

The deltoids have three distinct parts: the anterior deltoid, lateral deltoid, and posterior deltoid. This muscle group helps move the upper arm and stabilizes the shoulder joint.

deltoid heads

The deltoids' primary function is to move the humerus and shoulder joint simultaneously. These muscle movements are abduction (lifting the arm outward from the side), flexion (lifting the arm to the front and overhead), extension (pulling the arm behind the body), and rotation (humerus rotates in the shoulder socket).

The deltoids mainly control the trajectory of your punch, whether it is a jab, a hook, an uppercut, or a straight cross. It initiates the movement that begins with the arm's starting position, usually with elbows at the side or back of the body. When executing a straight cross, the deltoids flex the shoulder with a slight abduction at the start of the punching motion.

Serratus Anterior

A fan-shaped muscle, the serratus anterior originates on the first to eighth or ninth ribs at the lateral wall of the thorax and inserts along the superior angle, medial border, and inferior angle of the scapula.

serratus anterior

The "boxer's muscle" or anterior serratus is mainly responsible for the protraction of the scapula. Such movement is exhibited when throwing a punch.

Triceps and Hand Muscles

The triceps brachii is a large, thick muscle on the posterior part of the upper arm with an appearance resembling that of a horseshoe. The triceps provide elbow extension during a punching motion.

triceps anatomy

The finger extensors and flexors provide stability at impact. The finger extensors of the arm tighten to stabilize the wrist, while the finger flexors contract to close the fist.

Here Comes the Snap

A punch needs momentum to be effective.

Momentum is mass multiplied by velocity, meaning additional mass or velocity equals more significant momentum. Strength training for the arms may add speed and mass for greater momentum, but this course of action has limitations as a boxer has to compete within a particular weight requirement.

The only option left is to take advantage of advances in the study of kinesiology and biomechanics to produce additional momentum for a punch. We have already discussed that the most powerful punches start from the foot and link that kinetic energy to the leg, hips, trunk, shoulder, and arms. However, the story of the punch does not end there because here comes the “Snap” as its finale.

The snap of the punch is a quick and brief body stiffening, especially in the hands, arms, shoulders, and core, to efficiently transfer effective mass on the target upon impact. Studies have demonstrated that a double peak in muscle activation, as the snap provides, results in a more tremendous force on punch impact.

Speed, power, and agility are not enough to excel in boxing. As with other sports, technique and strategy are key factors that make a person the next great boxing champion. 

References

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2. Zohdi TI. On the biomechanical analysis of the calories expended in a straight boxing jab. J R Soc Interface. 2017;14(129):20170153. doi:10.1098/rsif.2017.0153

3. Filimonov, V. I.; Koptsev, K. N.; Husyanov, Z. M.; Nazarov, S. S.. Boxing: Means of increasing strength of the punch. National Strength and Conditioning Association Journal: December 1985 - Volume 7 - Issue 6 - p 65-66 

4. Dinu D, Louis J. Biomechanical Analysis of the Cross, Hook, and Uppercut in Junior vs. Elite Boxers: Implications for Training and Talent Identification. Front Sports Act Living. 2020;2:598861. Published 2020 Nov 26. doi:10.3389/fspor.2020.598861

5. McGill, Stuart M1; Chaimberg, Jon D2; Frost, David M1; Fenwick, Chad M J1. Evidence of a Double Peak in Muscle Activation to Enhance Strike Speed and Force: An Example With Elite Mixed Martial Arts Fighters. Journal of Strength and Conditioning Research: February 2010 - Volume 24 - Issue 2 - p 348-357
doi: 10.1519/JSC.0b013e3181cc23d5 

Debbie (Deb) started powerlifting and Olympic lifting in High School as part of her track team's programming; She continues to train in order to remain athletic. Inspire US allows Deb to share information related to training, lifting, biomechanics, and more.
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