Pediatric Physical Therapy:
Abstracts: Abstracts of Platform and Poster Presentations for the 2006 Combined Sections Meeting: Platform Presentations
1Biokinesiology & Physical Therapy, University of Southern California, Los Angeles, CA, USA (Kantak, Sullivan)
2Division of Occupational Therapy, University of New Mexico, Albuquerque, NM, USA (Burtner)
Motor learning studies in young adult and older populations demonstrate that reduced frequency feedback is more effective in the learning of motor tasks. However, it is unknown if these findings can be applied to motor learning in children, given that children have different information processing capabilities than adults. The purpose of this study is to determine the effect of different relative frequencies of knowledge of results (KR) on skill acquisition in healthy children compared to healthy young adults.
Number of Subjects:
10 healthy young adults (mean age: 26.7 yrs) and 6 typically developing healthy children (mean age:11.2yrs) participated in the study. All the participants were screened for visual perception and grip strength.
Participants practiced a discrete arm movement with specific spatiotemporal parameters using a light-weight lever. Participants from each group (adults and children) were randomly assigned to either a 100% feedback group or 62% feedback group. The 100% KR group received feedback about their performance after every trial while in the 62% KR group, the frequency of KR presentation was faded over trials. Feedback included a root mean square error (RMSE) and the participants' actual movement trajectory superimposed on the target waveform. All subjects practiced the task for 200 trials (four 50-trial blocks) on day 1 and returned next day for a 10-trial retention test. Performance was measured as the RMSE between the target and the participants' response.
During the acquisition phase, adults performed with significantly less error than the children (P = 0.029). Further, children who practiced the task with reduced frequency of feedback had a significantly higher error than the other three groups (P = 0.04). For the retention test, adults who practiced with 62% KR (error score: 16.04 + 4 deg) performed as accurately as those who practiced with 100% KR (14.42 + 4.6 deg). However, the children who received KR on all trials (11.93 + 3.5 deg) performed with less error on the retention test than those who received KR on 62% of the trials (17.41 + 2.4 deg). This difference was not statistically significant (P = 0.09); however the effect size was 1.7, indicating a strong effect, considering the small sample size and preliminary analysis at this point in this study.
During motor learning of a discrete task, children use feedback in a manner that is different from that used by adults. The results suggest that reduced feedback frequency during practice is not as effective in motor performance and learning in children as is typically reported in the adult motor learning literature.
Training and intervention effectiveness can be enhanced by the appropriate use of feedback during motor skill learning in children with and without disability. Further work is needed to understand the generalizability of motor learning principles to children learning motor tasks.