Interactive effects between group and single-subject response patterns

Janet S. Dufek, Barry T. Bates, Nicholas Stergiou, C. Roger James

Research output: Contribution to journalArticlepeer-review

50 Scopus citations


A two-part study was undertaken to investigate the effects of movement experiences on lower extremity function during impact activities. Group and single-subject performances were evaluated for a total of 12 male volunteers during landing (Study I) and running (Study II) activities. Standard biomechanical techniques were used to obtain kinematic (200 Hz) and kinetic (1000 Hz) data during soft, normal and stiff-knee landings (Study I) and for under, normal, and over-stride running (Study II). Performance trials were tested for normality, condition differences were documented and multiple regression models were computed to predict the first (F1) and second (F2) maximum vertical forces during landing and the maximum impact force (IF) during running. Results of the study identified condition differences with no deviations from normality, thereby achieving the goal of increasing performance heterogeneity to benefit the modeling procedures. Group regression model results for F1, F2 and IF each identified a single predictor variable that accounted for 74.7, 98.6 and 81.6% explained variance (EV), respectively. Single-subject predictors and EV values varied and demonstrated a number of different strategies. The group models were not representative of any of the individual subjects' performances and indicate that group models can describe a mythical "average" performer. These results suggest that researchers must be cautious when evaluating group performance patterns.

Original languageEnglish (US)
Pages (from-to)301-323
Number of pages23
JournalHuman Movement Science
Issue number3
StatePublished - Oct 1995
Externally publishedYes

ASJC Scopus subject areas

  • Biophysics
  • Orthopedics and Sports Medicine
  • Experimental and Cognitive Psychology


Dive into the research topics of 'Interactive effects between group and single-subject response patterns'. Together they form a unique fingerprint.

Cite this