Most individuals who have recovered from COVID-19 may have long-lasting systemic impairments. Previous studies have already demonstrated balance changes both in asymptomatic athletes and in patients who manifested the moderate to severe form of COVID-19. Balance uses information from the vestibular, ocular and proprioceptive systems that act in synergy to maintain posture in different conditions, called static and dynamic balance. The simultaneous impacts on static and dynamic balance and possible relationships with muscle strength and functional tests are still unknown in the scientific literature.

To compare static and dynamic balance in volunteers with long-term COVID-19 who had the severe form of COVID-19, compared to individuals who did not have a diagnosis of COVID-19.

Ambispective observational study of the case-control type, being the case, volunteers who presented the severe form of COVID-19, and control, with asymptomatic patients. The volunteers were evaluated after 6 months of hospital discharge, in a university research laboratory. Static balance was assessed using baropodometry and stabilometry and dynamic balance using the MiniBest Test. Muscle strength was assessed by isometric contraction of quadriceps extension and flexion and the 1-minute sit-to-stand test (1MSTS).: Most individuals who have recovered from COVID-19 may have long-lasting systemic impairments. Previous studies have already demonstrated balance changes both in asymptomatic athletes and in patients who manifested the moderate to severe form of COVID-19. Balance uses information from the vestibular, ocular and proprioceptive systems that act in synergy to maintain posture in different conditions, called static and dynamic balance. The simultaneous impacts on static and dynamic balance and possible relationships with muscle strength and functional tests are still unknown in the scientific literature.

Sample of 29 individuals, age 55±12.71, 12% female and 17% male BMI of 27.12± 4.23 /m², 38% were sedentary, 62% active, 14 (48.20 %) of the case group (COVID-19). Baropodometry revealed important changes in static balance, specifically in anteroposterior displacements, while performing simple activities with eyes open (2.12±2.18 vs. 1.6±0.57, p=0.05) and eyes closed (3.57±0.98 vs. 2.12±1.32, p =0.05). Stabilometry revealed alterations both in the total postural stability test (TSP) (2.52±2.31 vs. 1.40±0.54, p=0.05) and in the fall risk test (TRQ) (4.93±1.97 vs. 2.65±1.36, p=0.05). As for dynamic balance, the Minibest test also revealed changes in the COVID group (24.57±4.38vs 27,820.57, p=0.05) or? p=0.005?). Isometric muscle strength was lower in the COVID group only for extension (111.5±39.7 vs. 152.8±64, p=0.047), a behavior also observed by the 1MSTS (19.14±-5.47 vs. 27.58±-8.14, p=0.05).

Late changes in static and dynamic balance were found in patients who had the severe form of COVID-19, as well as reduced lower limb strength, functionality and increased risk of falling.

Understanding the late impacts of COVID-19 on static and dynamic balance, and muscular and functional mechanisms involved, are crucial for the development of effective rehabilitation strate.