One Strong Arm Has a Cost: Wheelchair Table Tennis Shows 17% Strength Imbalance Across Six Para Sports

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Table tennis is a one-handed sport played from a seated position. For a wheelchair player, the racket arm drives every stroke, every serve, every recovery reach, while the other arm handles daily propulsion, transfers, and door handles. Researchers in Chile have now put a number on what that division of labor costs. In the first study to compare upper-limb asymmetry across wheelchair para sports, table tennis players showed a 17.5% average strength imbalance between their dominant and non-dominant arms, above the 15% threshold clinicians associate with elevated overuse injury risk.

The study, published in Frontiers in Sports and Active Living in July 2026, examined 30 athletes from the Chilean national Paralympic team during the 2024 season. All were international-level wheelchair users competing in six disciplines: wheelchair basketball (9 players), wheelchair rugby (7), table tennis (6), boccia (3), powerlifting (3), and wheelchair handball (2). Researchers measured strength and range of motion across seven upper-limb movements using a validated portable dynamometer and inclinometer, then calculated the percentage difference between limbs for each athlete. Spinal cord injury was the most common underlying condition, affecting 14 of the 30 participants.

Where Table Tennis Lands

The six table tennis players, competing in impairment classes C1 through C4, posted a total upper-limb asymmetry index of 17.54% (standard deviation 6.72). Their shoulder abduction imbalance alone averaged 22.6%. That placed table tennis firmly in the asymmetric group, alongside boccia (30.27%) and wheelchair rugby (26.33%).

The symmetric group told the opposite story. Wheelchair handball (10.00%), wheelchair basketball (12.17%), and powerlifting (about 10%) all stayed below the threshold. The pattern makes mechanical sense. Basketball and handball demand constant direction changes, sprinting, and ball handling with both hands. Powerlifting is explicitly bilateral. Table tennis, by contrast, concentrates thousands of repetitions into a single arm, and boccia and rugby add severe trunk and limb impairment on top of one-sided technical demands.

When researchers compared the asymmetric sports against the symmetric ones, the differences reached statistical significance in four strength measures (shoulder abduction, flexion, extension, and internal rotation, all p < 0.05) and three range-of-motion measures (shoulder abduction, adduction, and flexion, all p < 0.05). Notably, the asymmetric groups recorded higher absolute strength values, meaning the dominant arm was not simply weaker on the other side; it had grown stronger through use while the non-dominant arm trailed behind.

Why an Imbalance Matters More in a Wheelchair Athlete

For an able-bodied tennis player, a 17% arm-to-arm difference is a training question. For a wheelchair user, it compounds with a second load the study’s authors call an increased risk of shoulder overload during wheelchair propulsion. The same shoulders that play table tennis also push the chair through daily life. Sport-specific asymmetry stacks on top of that baseline rather than replacing it.

The clinical concern is supported by a 2026 survey of 61 wheelchair rugby athletes in the United States, published in Assistive Technology. Their average score on the Wheelchair User’s Shoulder Pain Index was 56.08 out of 100, reflecting high pain levels in a population whose sport shares the asymmetric profile of table tennis. That survey also found protective associations worth acting on: more years of wheelchair use (r = -0.48), more adaptive sports participation (r = -0.47), regular warm-ups (r = -0.53), and shoulder strength training (r = -0.34) all correlated with lower pain scores, while power wheelchair use correlated with higher pain (r = 0.51). All correlations were significant at p < 0.001.

The prevention evidence is thin but points the same direction. A 2024 scoping review in the American Journal of Physical Medicine and Rehabilitation screened 785 articles and found just four injury-prevention studies in wheelchair sports, all in basketball and rugby. Those programs increased shoulder range of motion, decreased shoulder pain, and reduced cumulative traumatic disorders. The review’s conclusion applies directly to para table tennis: prevention programs for adaptive athletes exist, work, and remain barely studied.

What Coaches and Players Should Take From This

The study does not say table tennis is dangerous for wheelchair users. Its athletes were healthy enough to pass screening, and anyone excluded for an upper-limb injury in the previous six months or pain of 5 out of 10 or worse on test day did not participate. What it says is more precise: the sport builds the playing arm faster than the other one, and the gap crosses a recognized risk threshold.

Three practical responses follow from the data. First, measure. A portable dynamometer assessment takes minutes and gives coaches a baseline asymmetry number per athlete. Second, train the non-dominant side deliberately. The rugby survey found shoulder strength training associated with meaningfully lower pain, and the prevention review found structured programs improved range of motion and reduced pain reports. Third, warm up as a rule rather than a habit, since warm-up frequency showed the strongest protective correlation (r = -0.53) of any behavior measured.

The authors are candid about limits. Six table tennis players is a small sample, all from one national team, in a cross-sectional design that shows association rather than causation. Impairment severity, which likely drives part of the asymmetry pattern, was not formally assessed. These are reasons for larger multi-country studies, not reasons to ignore the finding.

Para table tennis is growing, and its inclusion in the Paralympic program gives thousands of wheelchair users a sport that fits their bodies and their lives. This study adds a maintenance item to that invitation: the arm that plays the game deserves a training plan, and so does the one that does everything else.