Background: Measurement of passive ankle dorsiflexion range of motion (ADROM) is often part of a physical therapy assessment. Objects: The objective of this study was to identify the effects of subtalar joint neutral position (SJNP) on passive ADROM according to knee position in young adults. Methods: We recruited 14 young adult participants for this study. Two examiners used a universal goniometer to measure passive ADROM with and without SJNP. Dorsiflexion force was applied to the forefoot until maximum resistance was reached in two knee positions (extension and 90˚ flexion) in the prone position. Subtalar joint position was also recorded at maximum ADROM. Passive ADROM was measured three times at different knee and subtalar joint positions, in random order. Two-way repeated-measures analysis of variance was used to compare the effects of subtalar joint and knee position on passive ADROM. Results: Passive ADROM was significantly lower with than without SJNP during both knee extension (mean difference: 7.4˚) and 90˚ flexion (mean difference: 16.9˚) (p<.01). Passive ADROM was significantly higher during 90˚ knee flexion than during knee extension both with (mean difference: 5.8˚) and without SJNP (mean difference: 15.2˚) (p<.01). The valgus position of the subtalar joint was significantly lower with than without SJNP during both knee extension (mean difference: 3.3˚) and 90˚ flexion (mean difference: 4.3˚) (p<.01). Conclusion: Our results indicate that the gastrocnemius may limit ankle dorsiflexion more than the soleus does. Greater dorsiflexion at the subtalar and midtarsal joints was observed during passive ADROM measurement without than that with SJNP; therefore, SJNP should be maintained for accurate measurement of ADROM.

The purpose of this study was to analyse the subtalar joint movement characteristics in human stance phase. The data of subtalar joint movement patterns are collected by CTA(calcaneus to tibia angle) measurements. CTA is defined as a angle formed between the bisect of the posterior shank and bisect of the posterior heel, as determined by placement of the retroreflective markers. The angle measured in degrees. The participants are 74 healthy individuals (37 men and 37 women) who have no orthopedic and neurological impairment, aged from 19 to 29 years(mean 22.95). Prior to participation, each subjecct informed the procedures of experiment from researcher and assistant researcher. The equipments of this study are walking grid, marking tapes, goniometer, video camera, monitor and ink for foot print are used in the study. In order to determine the statistical significance of result, the paired t-test and Pearson correlation were applied at the 0.05 level of significance. The results were as follows : 1. The reliability of measured CTA value are showed a high correlation, ranged from .86 - .94. 2. The mean value of step width are 7.67cm in men and 6cm in women. So, significant difference between men and women in 0.05 level of significance. 3. There was significant difference between man and women's TOA(toe out angle)(p<0.05). 4. The CTA of female's is more higher than male's one, however not statistical difference between man and women(p>0.05). 5. The CTA is reduced according to increasing TOA(p<0.05).