Recruiting at schools was slower than planned. Missing data higher than acceptable.

A large study in Mallorca, Spain showed that nonspecific low back pain is quite prevalent in adolescents 13-15 years of age (Kovacs, 2003). Since below the age of seven years hardly any child has suffered low back pain, the purpose of this study is to determine the prevalence of low back pain in children 10-12 years of age, and to investigate the risk factors associated with its occurrence.

Inclusion Criteria:

• Schoolchildren born in the years 1993, 1994 or 1995
• Attending schools (public, concerted or private) in Mallorca
• Can read and write Spanish

Exclusion Criteria:

• Nor attending class on the days when the study is being done

All 10-12 year old schoolchildren on the island of Mallorca, Spain