Muscle oxygen saturation and cutting movements in Women's Futsal

The evaluation of muscle oxygen saturation (SmO 2 ) using non-invasive near-infrared spectroscopy (NIRS) technology has been developed in sports performance settings, though few studies have utilized it for injury prevention. This study aimed to assess and correlate bilateral SmO₂ with injury risk during a repeated sprint ability test with change of direction (RSA-COD), using the Cutting Movement Assessment Score (CMAS). Fourteen female futsal players (age 22.5 ± 4.6 years) participated. The RSA-COD consisted of eight 25-meter sprints with COD at 15 m and 3 m, with speed (m·s 2 ) recorded. Additionally, shot accuracy was evaluated using a goal-scoring point system. Knee injury risk was assessed using the CMAS, while NIRS sensors were placed bilaterally on the gastrocnemius muscles of the dominant (DL) and non-dominant (non-DL) legs during the RSA-COD. Bilateral differences were found in SmO₂ data, muscle oxygen extraction (▽%SmO₂), and total hemoglobin (tHb). Additionally, three players (21.4%) showed a high risk of injury, while 10 players (71.4%) had a medium risk at 15 m. At 3 m, three players (21.4%) had a high risk, and six players (42.8%) had a medium risk. The results indicated that ▽%SmO₂ is associated with a higher risk of injury ( r = -0.48, p = 0.041) in the CMAS test. Therefore, exploratory study suggests that bilateral differences in SmO 2 data may be related to injury risk. Future studies should consider using two NIRS-sensors to detect potential metabolic imbalances between limbs.