Mattie E Pontiff ^1,2 Abhinandan Batra ³ Li Li ⁴ Noelle Moreau ^5*

• ¹ Department of Physical Medicine and Rehabilitation, School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado, United States
• ² Center of Innovation for Veteran Centered and Value Driven Care, Rocky Mountain VA Medical Center, Aurora, United States
• ³ Department of Physical Therapy, University of Louisiana- Monroe, Monroe, United States
• ⁴ Department of Health Sciences and Kinesiology, Georgia Southern University, Statesboro, United States
• ⁵ LSU Health Sciences Center New Orleans, Louisiana State University, New Orleans, United States

The purpose of this study was to investigate the relationships between a Power Leg Press test (PLP) with walking capacity and self-reported performance and participation in individuals with Cerebral Palsy (CP), and to compare the strength of the associations between two power tests (PLP and isokinetic (IsoK)) with walking capacity. Methods: Ambulatory individuals with CP (n=33; age 17.89(7.52)years) performed 5 inclined power leg presses at 40-50% of their 1-repetition maximum "as fast as possible". A linear position transducer was attached to the weight bar, and the displacement, total load, and angle of the sled were used to calculate peak power for each trial. Isokinetic knee extensor power was measured at 60 deg/sec. Walking capacity was measured using the 10-meter walk test fast (FS) and self-selected (SS) speeds and the 1-minute walk test (1MWT). Self-reported performance and participation measures were the Activities Scale for Kids-performance (ASKp), Patient-Reported Outcomes Measurement Information System (PROMIS), and the Gait Outcomes Assessment List (GOAL). Pearson's correlation coefficients determined relationships between power measures with walking capacity and self-report measures(p<.05). Results: PLP and IsoK power were significantly correlated to SS (r=.361, r=.376), FS (r=.511, r=.485), and 1MWT(r=.583. r=.443), respectively (p<.05). There was no significant difference between the strength of the associations between walking capacity and each test of power (PLP and Isok) (p>.05). PLP power was significantly correlated to composite scores on the ASKp (r=.690) and GOAL (r=.577) and to 4 components of the PROMIS, including physical function (r=.588)(p<.01). The Gait and Mobility subscale of the GOAL (r= .705) and the Locomotion (r=.636), Transfers (r=.547), and Standing (r=.521) subscales of the ASKp had strong relationships to peak power produced during the PLP test (p<.01). Discussion: PLP power was significantly correlated with walking capacity and self-reported walking performance and mobility-based participation in ambulatory individuals with CP. Higher movement velocities associated with the PLP test may explain the significant associations of power with faster gait speeds. Self-reported mobility performance and physical activity showed moderate to strong relationships with lower extremity power. Overall, these results suggest a strong link between decreased muscle power generation and walking limitations in individuals with CP.