Seefeldt`s classic motor development pyramid model recognizes the significance of fundamental movement skills (FMS) in physical activities and proposes a “proficiency barrier” between FMS and higher-level specific sports skills during middle childhood. However, the relationship between the layers of the conceptual model has not been empirically tested. This study investigated motor fitness (MF), FMS, and quality of movement patterns (QMP) in 7–10 years old children and evaluated the relationships among them. A total of 117 children were randomly selected to take tests of MF, the Test of Gross Motor Development-2 (TGMD-2), and the Functional Movement Screen (FMS™). MF and FMS levels were classified according to percentile ranges. Two multiple (R×C) Chi-Square tests were applied to analyze the relationships between MF, FMS, and QMP. Post-hoc testing estimated the possibility of FMS and QMP to predict MF. The results showed that boys scored significantly higher on the object-control subtest and on the TGMD-2 compared to girls (p<0.001), while girls scored significantly higher on the FMS™ (p = 0.001). FMS score and QMP level were weakly correlated with MF (FMS: χ2 = 14.605, p = 0.006, Cramer`s V = 0.25; QMP: χ2 = 13.943, p = 0.007, Cramer`s V = 0.24). Thus, 60.5% of children with “excellent” FMS and 59.6% with “high” QMP were categorized as having a “good” MF. In contrast, only 23.1% of children with “poor” FMS and 24.3% with “low” QMP were classified as having a “good” MF. Our results confirm MF, FMS, and QMP are correlated with each other, although this relationship is weak. Further, a possible motor skill proficiency barrier exists already in children 7–10 years old. The study results support the promotion of physical activity and motor skill development in primary school children.