Although it is well known that foam rolling (FR) of the lower extremities can increase the range of motion (ROM) of a joint while likely having no detrimental effect on muscle performance, to date, this is not clear if this is the case for the upper body. Therefore, the purpose of this study was to analyze the effects of a 2-min FR intervention of the pectoralis major (PMa) muscle on muscle stiffness of the PMa, shoulder extension ROM, and maximal voluntary isometric contraction (MVIC) peak torque. Thirty-eight (n = 15 females) healthy, physically active participants were randomly assigned to either an intervention (n = 18) or a control group (n = 20). The intervention group performed a 2-min foam ball rolling (FBR) intervention of the PMa muscle (FB-PMa-rolling), while the control group rested for 2 min. Before and after the intervention, muscle stiffness of the PMa was measured with shear wave elastography, while shoulder extension ROM was recorded with a 3D-motion capture system, and shoulder flexion MVIC peak torque was measured with a force sensor. MVIC peak torque decreased in both groups (time effect: p = 0.01; η² = 0.16), without any difference between groups (interaction effect: p = 0.49, η² = 0.013). ROM (p = 0.24; η² = 0.04) and muscle stiffness (FB-PMa-rolling p = 0.86; Z = -0.38; control group p = 0.7, Z = -0.17) did not change due to the intervention. The lack of changes in ROM and muscle stiffness following the FBR intervention might be explained by the small area of applied pressure with the FBR on the PMa muscle. Moreover, the decrease in MVIC peak torque is likely more related to the uncommon test situation of the upper limbs, rather than the FBR intervention itself.

• This was the first study to explore the acute effects of a foam ball rolling exercise of the pectoralis major (pars clavicularis) muscle on range of motion, maximum isometric contraction, and muscle stiffness.

• A 2-min foam rolling exercise of the pectoralis major (pars clavicularis) muscle with a foam rolling ball has no acute effects on shoulder extension ROM or muscle stiffness.

• Strength measures (i.e., MVIC peak torque) showed a time effect in the mixed factorial ANOVA, indicating a decrease in physical performance in both groups.