Instrument-assisted soft tissue mobilization (IASTM) is a common intervention among clinicians. Despite the popularity, little is known about the forces applied by the clinician with the instruments during treatment. The purpose of this investigation was to examine the forces applied by trained clinicians using IASTM instruments during a simulated treatment. Eleven IASTM trained (Graston Technique, Técnica Gavilán, or RockBlades) clinicians (Physical Therapist = 2, Chiropractor = 2, Athletic Trainer = 7) participated in the study. Each clinician performed 75 two-handed strokes distributed evenly across five different IASTM instruments on a skin simulant attached to a force plate. IASTM stroke application was analyzed for peak normal forces (Fpeak) and mean normal forces (Fmean) by stroke. We observed an average Fpeak of 8.9N and Fmean of 6.0N across all clinicians and instruments. Clinicians and researchers may use the descriptive values as a reference for application of IASTM in practice and research.