The Investigation of Ground Reaction Forces to Validate Progression of Plyometric Exercise: A Pilot Study
Abstract
Purpose. Current approaches lack research toward rehabilitation of the lower extremity following injury regarding progression and the effects of ground reaction forces (GRFs) along the kinematic chain. A typical physical therapy protocol demonstrated the patients initially performing non-weight bearing, or open chain exercises followed by walking and running activities. This initial pilot study entertained the need for a more “seamless” progression of exercises to bridge the gap of GRFs when rehabilitating a weight bearing joint from walking-to-running in healthy individuals. Methods. 10 plyometric exercises were chosen for the study following careful review of evidence-based literature and researched protocols for strength and conditioning. Data was gathered from 11 physically active subjects. Subjects performed each plyometric exercise multiple trials while GRFs were recorded on a single force plate. Assessment was focused on the vertical GRFs for the dependent variable specifically. The vertical forces produced by each plyometric exercise were quantitatively rated in ascending order with a one-way ANOVA and paired t-test were performed between exercises and treadmill speeds. GRFs during walking and running for each participant were also gathered to investigate where the particular exercise fell in relationship to the values on a force plate treadmill. Results. Mean values for each plyometric exercise ranged from .93 x BW to 2.24 x BW. Conclusions. Based on the data that we measured and assessed, we conclude that the GRFs reported from this exploratory study appears the possibility that plyometric exercises represent a valid foundation which to further our investigation into exercise progression. A follow up study is warranted on injured or post-operative patients to assess the safety and effectiveness of plyometric rehabilitation progression. Additionally, further investigations justify the use of twin force plates to investigate individual lower extremity values during double limb landing.