Effects of stiffness-altered compression garments on lower-limb angular kinematics and force-time characteristics in...

Compression garments (CGs) with localized stiffness alterations are marketed to enhance athletic performance, yet evidence for benefits in jumping remains limited. This study aimed to evaluate the effects of stiffness-altered CGs on lower-limb angular kinematics and force-time characteristics in countermovement jumps (CMJs).

62 physically active adults (31 female, 31 male) performed CMJs under four conditions: control (shorts only), knee sleeves with stiffness components, compression leggings without stiffness alterations, and stiffness-altered compression leggings. Sagittal-plane angles were recorded via motion capture, and vertical ground reaction forces via force platforms. Two-way (sex*condition) ANOVA were performed for derived variables, employing both discrete and one-dimensional statistical parametric mapping (SPM) analyses.

Both leggings conditions significantly restricted hip range of motion (81-82° vs. non-leggings 85°, p = 0.001) and peak extension velocity (455-461°/s vs. non-leggings 512°/s, p < 0.001) relative to non-leggings conditions. SPM further revealed phase-specific effects, such as slower hip flexion during early unweighing phase (p < 0.001) in stiffness-altered leggings. Knee and ankle kinematics were not affected. In addition, stiffness-altered leggings reduced countermovement speed (1.37 m/s vs. control 1.43 m/s, p = 0.018) and braking impulse (1.37 N s/kg vs. control 1.43 N s/kg, p = 0.017) but did not impair jumping height (∼0.3 m) and propulsive impulse (∼2.5 N s/kg). No sex-by-condition interactions were observed. No significant differences were found between the two non-leggings conditions, nor between the two leggings conditions.

Despite no detectable performance decline, compression leggings primarily restricted hip motion and altered eccentric phase characteristics in CMJs, likely diminishing stretch-shortening cycle efficiency. To promote beneficial effects of stiffness-altered CGs, future study designs shall control for garment fitting via compression and stiffness measurements, as well as individual variations in skill levels via more specific and representative sampling.