tennisquestions

Tennis: a smashing history of how rackets shaped the game

The start of the Australian Open, the year’s first tennis grand slam, means that metrics like points gained, serve speeds, and shot placement will be discussed in depth. Although several of these success indicators can be applied to the player, we should also take into account the racket’s importance.

Tennis is a long-established sport with a long history of equipment advancements. The first Australian Open was held in 1905, and Wimbledon, the oldest tennis tournament, was created in 1877. As detailed in a recent research article and summarised in the video below, the tennis racket has improved significantly since these early competitions due to the application of advanced engineering.

Early tennis rackets were inspired by the older sport of real tennis, a racket sport common among the wealthy and elite dating back to the 16th century. They were made of wood and had long handles and small lopsided heads, making it easier for the player to put the hitting surface down to the ground and strike the low-bouncing balls that are characteristic of real tennis. This were quickly phased out as tennis evolved into a stand-alone sport. By the time of the first Australian Open, symmetrical racket frames were becoming commonplace.

Metal provides less damping than wood, resulting in sharper vibrations if the player mishits the ball, and the metal frame often damages the natural gut strings at the point of contact. The Dayton Steel Racket Corporation tried using more sturdy metal strings, but they harmed the ball’s felt cover and were susceptible to rusting.

A technological revolution is underway.

The beginning of the open era in 1968, when professionals and amateurs started vying for cash prizes, was most likely a major factor in the rapid growth of tennis rackets during this time span. During the 1960s, wooden rackets were still the most common, but fibreglass-reinforced composite materials began to appear as a reinforcement on wooden frames, such as the Slazenger Challenge Power and Wilson Kramer Cup.

Racket designers were experimenting with a variety of materials by the 1970s, including wood, fiber-reinforced composites, aluminium, and steel. The Classic by Prince, based on a 1976 patent from Howard Head, was a famous racket during this period. Since the Classic was made of aluminium, it had a much wider head than its wooden counterparts, making it easier to strike the ball. Earlier metal rackets had string (now synthetic) harm, so plastic grommets were used to solve the problem.

High-end tennis rackets have been made from fibre-reinforced composite materials including fibreglass, carbon fibre, and aramid since the 1980s (strong synthetic fibres). The high stiffness and low density of these composite materials, combined with their manufacturing flexibility, give them an edge over wood and metal. Since composites allow the racket engineer to control the positioning of various materials across the frame, they have more control over parameters such as the form, mass distribution, and stiffness of the racket.

Composite rackets have wide, hollow cross sections for high stiffness and low mass, whereas wooden rackets have thin, solid cross sections. The introduction of “widebody” rackets, such as Wilson’s Profile, in the late 1980s demonstrated the increased design freedom provided by composites. Widebody rackets have wider cross sections around the centre of the frame than the handle and tip, resulting in increased stiffness in the highest bending area.

Interaction between the player and the racket

Composite rackets have a higher stiffness, which means they lose less energy to vibrations upon contact, allowing the player to hit the ball harder. When using a racket with a wide head and a high stiffness, however, there is a greater chance of overuse injury to the shoulder. A lighter modern racket with a lower swingweight (moment of inertia around the handle) is often easier to wield, and players prefer to swing it faster during strokes.

Despite the higher swing speed obtained with a lighter racket, ball speeds remain identical because the increased racket speed is offset by the reduced striking mass. Rather than a one-size-fits-all solution, there is likely an optimal racket for each player, and player preference is a significant factor. In the future of tennis racket design, customisation strategies and player tracking using sensor and camera systems are likely to play a key role.

Modern composite tennis rackets are manufactured with labor-intensive, environmentally unfriendly methods. More renewable products, such as recycled and natural fibre composites, and more automated manufacturing methods, such as additive manufacturing, could be explored by racket manufacturers. We could use a sensor to track how a player swings a racket and then make them a custom racket that is tailored to their playing style.

The evolution of the racket has been linked to the creation of the tennis on show at the Australian Open. According to studies, a player could serve the ball 17.5 percent faster with a new racket than they could with the first rackets used in the 1870s. No doubt, advancements in racket design will continue to influence the sport in the future.