Results. Significant differences were found between the 2 groups on taut tendon,
relaxed muscle length (AO); taut tendon, stretched muscle length (AMax); and muscle
stretch (AO to AMax). Infants born preterm demonstrated measures of AO and AMax in
positions of greater plantar flexion compared with infants born full term. Significant
differences in measurements of AO were found between term age and 12 weeks of
age, indicating that the tendon lengthens during this period for both groups.