An exploration of the relationship between newly identified patterns of propulsion technique, measures of lower limb impairment and performance in RaceRunning athletes
Background RaceRunning allows people with neurological conditions leading to hypertonia, ataxia and/or athetosis to participate in sport both recreationally and competitively. The ‘Petra racerunner’ is a 3 wheeled bike with saddle, chest plate and handles with no pedals. Due to the partial weight bearing element and variety of coordination impairments among athletes, different patterns of propulsion technique are thought to exist that will ultimately affect performance. A better understanding of these types of technique will provide valuable information for the development of evidence-based classification, however no previous research has explored this area. Therefore, the aims of this current research project were threefold: a) Identify patterns of propulsion technique in RaceRunning athletes and develop classification criteria for each group, b) Examine the reliability of these newly developed classification criteria and c) Investigate the relationships between patterns of propulsion technique, measures of impairment and performance. Methods Videotaped observational gait analysis was performed on footage of twenty-two RaceRunning athletes (Aged 16-42) with neurological conditions (CP (21), ABI (1)), taken from a primary study (Van der Linden et al. 2018). Through a systematic process, RaceRunning athletes were sub-divided into different groups based on running style. The groups were named, and classification criteria was developed based on distinguishable kinematic characteristics. Three researchers (including the author) then rated the RaceRunning athletes with strict use of the classification criteria. Fleiss’ Kappa coefficient was used to assess the reliability. Excel software and non-parametric descriptive statistics were then used to examine the relationship between several measures of LL impairment (passive ROM, strength (MMT), Spasticity (ASAS and MAS), Selective Voluntary Motor Control (SCALE)), propulsion technique and performance. Results Five distinct patterns of propulsion technique were identified. An overall strong (K = .857) statistically significant (p < 0.0005) agreement was found between raters using the newly developed classification criteria. Strong statistically significant (p < 0.05) agreements were found for groups 1 (K = 1.0), 2 (K = .840), 3 (K = .878) and 5 (K = 1.0) while a good agreement was shown for group 4 (K = .728, P < 0.05). RaceRunning athletes with faster propulsion techniques (Groups 2, 3) presented with less spasticity, better passive Range of motion and more lower limb muscle strength compared to their counterparts. The speed of each group for the 100m sprint event ranged from 24.92-49.31 seconds. Conclusion It can be concluded that due to the design features of the Petra racerunner and variation in severity of coordination impairments five different patterns of propulsion technique exist in RaceRunning. RR athletes can be categorised into these groups using newly developed classification criteria which was proven to be a reliable tool. Relationships were shown between several measures of LL impairment and patterns of propulsion technique in RaceRunning. These findings can be used to inform future research.