Dynamic ultrasound assessment of tissue gliding dysfunction in marathon-induced muscle soreness: A pilot study

Delayed onset muscle soreness commonly occurs after exercise. Although tissue gliding dysfunction has been implicated in muscle soreness, its temporal changes remain undocumented in real-world endurance exercise settings. This study investigated temporal changes in both qualitative and quantitative aspects of tissue gliding before and after marathon running by using dynamic ultrasonography.

Two recreational marathon runners underwent ultrasonographic assessments of tissue gliding in the gastrocnemius muscle at baseline (pre-race) and daily for 5 consecutive days post-race (D1-D5). Pain on palpation was evaluated using the Numerical Rating Scale (NRS; 0-10). A reference dataset from healthy volunteers was used to contextualize pre-race values.

Both participants showed peak muscle soreness (NRS 5-6) on D1 and D2, accompanied by a reduction in tissue gliding distance (minimum 2.83 mm, baseline 6-7 mm). From D3 onward, pain decreased (NRS ≤1), and tissue gliding distance gradually returned to pre-race levels. Pre-race values were within the range observed in healthy volunteers, whereas D1 and D2 values fell below this range. Additionally, their baseline gliding patterns changed exclusively during peak soreness before returning to their original states.

The findings show that delayed onset muscle soreness leads to significant reductions in tissue gliding. These results highlight the importance of understanding fascial mechanics in the context of delayed onset muscle soreness and suggest that gliding dysfunction could serve as a key marker of muscle soreness and recovery.