A pilot investigation into the relationship between static diagnosis of ankle equinus and dynamic ankle and foot dorsiflexion during stance phase of gait: Time to revisit theory?

BACKGROUND:
Although the clinical assessment of ankle dorsiflexion has traditionally been measured utilising various goniometric means, the validity of this static examination has never been investigated. Since any impairment in ankle flexibility is likely to result in injuries, it is imperative that the correct examination technique is conducted.
HYPOTHESIS/PURPOSE:
To determine whether a clinical diagnosis of ankle equinus, or limited ankle dorsiflexion, correlates with a decreased dorsiflexion range of movement of the foot and ankle during gait.
METHODS:
Twenty participants with a clinical diagnosis of ankle equinus underwent optoelectronic motion capture utilising the Rizzoli foot model. Participants were divided into two groups, Group A with <-5° of dorsiflexion and Group B with -5° to 0° of ankle dorsiflexion.
RESULTS:
Participants in Group B had a mean dynamic ankle dorsiflexion angle of 13.9°, while those in Group A had a mean dorsiflexion angle of 4.4°, resulting in a significant difference (p=0.004) between the two groups. Likewise, foot mean dynamic dorsiflexion angle of Group B was 17.13° and Group A 8.6° (p=0.006).
CONCLUSION:
There is no relationship between a static diagnosis of ankle dorsiflexion at 0° with dorsiflexion during gait. On the other hand, those subjects with less than -5° of dorsiflexion during static examination did exhibit reduced ankle range of motion during gait.