Background: Physical activity level hinders all patients' ability to participate in physical 
therapy practices. However, physical therapists might benefit from knowledge about 
different patient groups' activity levels when implementing physical therapy programs.
Purpose: to compare the activity level of adolescents with a history of rheumatic fever 
and receiving penicillin injections with normal adolescents. Methods: This case control 
study was conducted on sixty adolescents, divided into two groups: group 1 (thirty normal 
adolescents) and group 2 (thirty adolescents receiving penicillin as prophylactic 
management at an outpatient clinic of the National Heart Institute). All participants were 
asked to answer the International Physical Activity Questionnaire-Short Form (IPAQ-SF) 
in order to evaluate their physical activity level. Results: A non-significant difference 
was found when comparing the means of groups 1 and 2 in age (p-value = 0.48), weight 
(p-value = 0.48), and height (p-value = 0.09). The Pearson chi square test showed a nonsignificant difference was found between male and female distribution within groups 1 
and 2 (p-value = 0.79). Significant differences were detected in the physical activity 
category distribution within groups 1 and 2 (p-value = 0.007). A non-parametric test 
(Mann-Whitney U test) showed a significant difference between group 1 and group 2 in 
MET-min per week (p-value = 0.0001). Conclusion: Activity level in adolescents with a 
history of rheumatic fever and receiving penicillin injection is lower than activity level in 
normal adolescents, so physical therapists should consider the physical activity level of 
adolescents who had rheumatic fever and received penicillin injection during evaluation 
and treatment as their activity level is significantly lower than average