Pronation of the foot is an essential motion of the normal function of the lower extremity. Its main contribution to the gait cycle is shock absorption and adaptation of the weight bearing foot to the surface. Hyperpronation is defined when hind foot motion is excessive, prolonged, and/or occurs in inappropriate timing of the stance phase. Hyperpronation of the foot may cause malalignment of the lower extremity and frequently leads to injuries to joints, tendons, knee pain and stress fractures. A review of the literature indicates that a correlation is found between hyperpronation of the foot and tibial rotation, patella and knww joint alignment. To our knowledge there is no evidence documented on the relationship between hyperpronation and pelvic alignment although, several researchers do suggest a possible connection. The purpose of this study is to examine the effect of hyperpronation of the feet on the lower limb and pelvic alignment.

Thirty-five healthy subjects (15 men and 20 women, age ranged from 23 to 33 years) were put into hyperpronation in standing position induced by wedges of different slopes of 10, 15 and 20 degrees. The base line for comparison was natural standing position and the sequence of trials was random. Each setting was maintained for 20 seconds and a sample of 4 seconds was processed and measured. Changes in the alignment of the lower extremity and pelvic were measured by a computerized system of motion analysis (VICON®).

Standing on the wedges induced hyperpronation with statistically significant increase in calcaneal eversion (p< .000). The results indicated that as a consequence to the usage of wedging on limb alignment, a statistically significant increase (paired t-test) in calcaneal valgus (p< .000), internal tibial rotation (p< .000), internal femoral rotation (p< .000) nd anterior pelvic tilt (p< .000) was found. A strong correlation (Pearson correlation coefficient) was found between segmental alignments in every two sequences positions (r = .612 up to .985). Five sets of mixed effects models for repeated measurement were built in all four positions. Results showed that the effect of the tibial alignment itself is responsible for the change in the pelvic position (p=.002).

These findings suggest that a correlation exists between motion at the distal segment (the foot) and the proximal segment (the pelvic) aof the body and indicate that hyperpronation and proximal postural malalignment are linked. This interaction between the foot and pelvic occurs in a chain reaction manner. Foot hyperpronation can influence pelvic alignment, only if significant change arises at the tibia.

The implication of this study advocates that when addressing pelvic and lower back dysfunction, the alignment of the foot should be examined as a contributing factor.

In addition, addressing foot malalignment is essential for treating and preventing pelvic and low back dysfunction.

Background: Ankle-foot orthoses (AFO) are frequently recommended to children with CP to improve their functional ambulatory ability, namely to increase walking velocity and stride length, and decrease cadence. Several studies examined the effectiveness of different types of AFOs based on gait analysis. AFOs however, are usually prescribed upon clinical examination alone. Based on our first year experience at the Dana Gait Lab not all AFOs improved function significantly.

Objective: To investigate the effect of prescribed AFOs on gait performance of children with cerebral palsy.

Methods: Twenty-two children with cerebral palsy (aage 5–17 y; gender: 11 males, 11 females, of them: 8 hemiplegic, 11 diplegic, 3 quadriplegic) were referred for full 3D instrumented gait analysis for different purposes. Using the Vicon 612 system they were studied walking both barefoot and with their prescribed AFOs. The two modes were compared in terms of spatio-temporal parameters and ankle-knee kinematics. Statistical analysis included paired t-test, and Pearson correlation coefficient; level of significance was set to .05.

Results: Using the prescribed AFOs, stride length was significantly increased (on average, 9.95±0.11 cm, p=0.000) while no significant changes were found in walking velocity and cadence (p= .111, p= .420, respectively). Split-by diaganosis revealed significant reduction in cadence (12.7 step/min, p=0.034) in the hemiplegic children. There was no significant improvement in the symmetry index of the stride length and step time due to the use of AFOs. Ankle and knee kinematics at initial contact and at loading response revealed non-significant changes. In the hemiplegic group knee flexion increased significantly (p=0.002) while ankle dorsiflexion at initial contact was almost significant (p=0.3).

The consistency of the results within subject and between modes was highly correlated (r=0.858–0.928) and statistically very significant (p< 0.000).

Discussion: In the current study, the only benefits of AFOs were increasing stride length and some improvement in ankle and knee kinematics. Our findings show that the use of an AFO, by itself, does not change dramatically other walking parameters. The high correlation between barefoot and AFO modes suggests that the child’s basic capability is the main factor that affects the gait pattern. Inappropriate AFO may partly be the reason for the non-significant results in this study.

We conclude that AFO’s should be given only after optimization of the child’s physical capabilities. Prescription should be made after careful evaluation using gait analysis whenever possible.