The assessment of muscle mechanical properties in multi-joint movements reveals inverse correlation of leg muscle force and power with gait transition speed.

Background: The impact that mechanical factors might have on gait reorganization was evaluated by the relationship between muscle mechanical capacity of isolated leg muscle groups and transition speed in previous studies. However, until now there are no studies that explored the relationship between muscle mechanical properties measured in cyclic multi-joint movements and gait transition speed.

Research Question: What is the nature of the relationship between gait transition speed and muscle mechanical capacities measured in cyclic multi-joint movements?

Methods: The sample included 18 physically active male adults, stratified by anthropometric dimensions. Individual walk-to-run (WRT) and run-to-walk transition speed (RWT) were determined using the standard incremental protocol. Mechanical capacities of leg muscles were assessed by linear force-velocity models obtained during treadmill locomotion and on bicycle-ergometer.

Results: The results revealed inverse correlation between WRT and RWT and maximal force assessed on treadmill (F; r = -0.57 and r = -0.54, respectively), as well with F (r = -0.65 and r = -0.58, respectively) and maximal power (P; -0.66 and -0.65, respectively) collected on bicycle-ergometer.

Significance: This study confirmed that mechanical muscle capacities are important physical limitation factors of transition speed, explaining over 36 % of the variance. The findings showed that a novel approach, with high biomechanical similarities with natural locomotion, revealed different results (negative correlations) in comparison to previous studies.