Effects of the AirLift PTTD brace on foot kinematics in subjects with stage II posterior tibial tendon dysfunction.
METHODS
Experimental laboratory study.


OBJECTIVE
To investigate the effect of inflation of the air bladder component of the AirLift PTTD brace on relative foot kinematics in subjects with stage II posterior tibial tendon dysfunction (PTTD).


BACKGROUND
Orthotic devices are commonly recommended in the conservative management of stage II PTTD to improve foot kinematics.


METHODS
Ten female subjects with stage II PTTD walked in the laboratory wearing the AirLift PTTD brace during 3 testing conditions (air bladder inflation to 0, 4, and 7 PSI [SI equivalent: 0, 27,579, and 48,263 Pa]). Kinematics were recorded from the tibia, calcaneus (hindfoot), and first metatarsal (forefoot), using an Optotrak motion analysis system. Comparisons were made between air bladder inflation and the 0-PSI condition for each of the dependent kinematic variables (hindfoot eversion, forefoot abduction, and forefoot dorsiflexion).


RESULTS
Greater hindfoot inversion was observed with air bladder inflation during the second rocker (mean, 1.7 degrees; range, -0.7 degrees to 6.1 degrees). Less consistent changes in forefoot plantar flexion and forefoot adduction occurred with air bladder inflation. The greatest change toward forefoot plantar flexion was observed during the third rocker (mean, 1.4 degrees; range, -3.8 degrees to 3.9 degrees). The greatest change towards adduction was observed during the third rocker (mean, 2.3 degrees; range, -3.4 degrees to 6.5 degrees).


CONCLUSIONS
On average, the air bladder component of the AirLift PTTD brace was successful in reducing the amount of hindfoot eversion observed in subjects with stage II PTTD; however, the effect on forefoot motion was more variable. Some subjects tested had marked improvement in foot kinematics, while 2 subjects demonstrated negative results. Specific foot characteristics are hypothesized to explain these varied results.
Neville
Christopher
C
Department of Physical Therapy Education, SUNY Upstate Medical University, Syracuse, NY13210, USA. nevillec@upstate.edu
Flemister
A Samuel
AS
Houck
Jeff R
JR
D000704:Analysis of Variance; D001696:Biomechanical Phenomena; D005260:Female; D006801:Humans; D008875:Middle Aged; D009989:Orthotic Devices; D037081:Posterior Tibial Tendon Dysfunction / Q000503:physiopathology / Q000628:therapy*; D016138:Walking / Q000502:physiology; D016474:Weight-Bearing / Q000502:physiology