Musculoskeletal pain and injury experienced by adolescents leads to behavioral, physical, and psychological consequences. Adolescents with recurrent pain are also more likely to carry these issues into adulthood. Dysfunctional movement, a suggested contributing factor, appears to increase as adolescents experience puberty. The purpose of this study was to investigate dysfunctional movement among a group of 9th-grade physical education students and to determine if a standardized, functional movement warm-up (FMWU) would improve movement quality more than regular physical education. Forty-four 9th-grade students were randomly assigned to a FMWU group (n = 22) and a regular warm-up (RWU) group (n = 22). The FMWU group completed the assigned warm-up 3 times per week over the course of 9 weeks except for one week only including one session, for a total of 25 total sessions. The Functional Movement Screen (FMS) was used to assess movement quality pre and post. Additionally, the lead researcher took notes of observed dysfunction while scoring FMS tasks. FMWU participant perceptions were collected by survey and the teacher’s perceptions were collected through a semi-structured interview. The results indicate a high rate of dysfunction among the group of ninth-grade participants. The total composite FMS mean score was 12.20 (SD = 1.56). Additionally, 45.5% of participants had at least one asymmetry and 93.2% scored a 1 on at least one FMS task. A mixed-design (Group x Time) analysis of variance (ANOVA) on the total composite scores revealed a significant group by time interaction, F (1, 42) = 11.27, p = .002. Paired samples t-tests for the FMWU group revealed significant improvement for the total composite score, deep squat (DS), rotatory stability (RS), and scores of 1. All other measures of movement trended positively for the FMWU group except the inline lunge (ILL), which remained the same. Whereas, the RWU group slightly or significantly worsened in the DS, ILL, and active straight leg raise (ASLR), and the hurdle step (HS) and total composite score did not change. Observations support the effect of the FMWU and 60% of FMWU participants reported liking the warm-up. The findings of this study suggest there is a high rate of dysfunctional movement among 9th-grade adolescents and an intentionally designed FMWU is an efficient way to address movement quality in physical education