A comparison of different over-the-counter foot orthotic devices on multi-segment foot biomechanics

Shoe collar height and heel counter-stiffness for shoe cushioning and joint stability in landing

This study examined the effects of shoe collar-height and counter-stiffness on ground reaction force (GRF), ankle and knee mechanics in landing. Eighteen university basketball players performed drop landing when wearing shoes in different collar height (high vs. low) and counter-stiffness (stiffer vs. less stiff). Biomechanical variables were measured with force platform and motion capturing systems. Two-way repeated measures ANOVA was performed with α = 0.05. Wearing high collar shoes exhibited smaller peak ankle dorsiflexion and total sagittal RoM, peak knee extension moment, but larger peak knee varus moment than the low collar shoes. Stiffer counter-stiffness shoes related to smaller ankle inversion at touchdown and total coronal RoM, but larger peak knee flexion and increased total ankle and knee sagittal RoM than the less stiff counter-stiffness. Furthermore, wearing stiffer counter-stiffness shoes increased forefoot GRF peak at high collar condition, while no significant differences between counter-stiffness at low collar condition. These results suggest that although higher collar height and/or stiffness heel counter used can reduce ankle motion in coronal plane, it would increase the motion and loading at knee joint, which is susceptible to knee injuries. These findings could be insightful for training and footwear development in basketball.

Bone Position and Ligament Deformations of the Foot From CT Images to Quantify the Influence of Footwear in ex vivo Feet

The mechanical behavior of the foot is often studied through the movement of the segments composing it and not through the movement of each individual bone, preventing an accurate and unambiguous study of soft tissue strains and foot posture. In order to describe the internal behavior of the foot under static load, we present here an original methodology that automatically tracks bone positions and ligament deformations through a series of CT acquisitions for a foot under load. This methodology was evaluated in a limited clinical study based on three cadaveric feet in different static load cases, first performed with bare feet and then with a sports shoe to get first insights on how the shoe influences the foot's behavior in different configurations. A model-based tracking technique using hierarchical distance minimization was implemented to track the position of 28 foot bones for each subject, while a mesh-morphing technique mapped the ligaments from a generic model to the patient-specific model in order to obtain their deformations. Comparison of these measurements between the ex vivo loaded bare foot and the shod foot showed evidence that wearing a shoe affects the deformation of specific ligaments, has a significant impact on the relative movement of the bones and alters the posture of the foot skeleton (plantar-dorsal flexion, arch sagging, and forefoot abduction-adduction on the midfoot). The developed method may provide new clinical indicators to guide shoe design and valuable data for detailed foot model validation.

Effect of a Commercially Available Footwear Insole on Biomechanical Variables Associated With Common Running Injuries

OBJECTIVE

To determine whether Dr. Scholl's Active Series (DSAS) footwear insoles alter biomechanical variables associated with running injuries.

DESIGN

Randomized, controlled experiment.

SETTING

Sport medicine and biomechanics gait analysis laboratory.

PARTICIPANTS

Fifteen healthy adults.

INTERVENTIONS

The control condition was the participant's own athletic footwear. The experimental condition was the participant's own athletic footwear plus a DSAS insole. Participants completed running gait analysis trials with each condition.

MAIN OUTCOME MEASURES

Peak vertical loading rates (VLRs), peak ankle eversion velocities (AEVs), peak ankle eversion angles (AEAs), and knee abduction angular impulses (KAAIs) were calculated and compared between the control and DSAS conditions because these variables have been associated with plantar fasciitis (VLRs), tibial stress syndrome (AEVs, AEAs), and patellofemoral pain syndrome (KAAIs).

RESULTS

Dr. Scholl's Active Series insoles reduced VLRs across participants by 16% (P < 0.001) but had no consistent influence on AEVs, AEAs, or KAAIs. Participant-specific responses showed that most runners either experienced AEA and KAAI reductions or no change with the DSAS insole, whereas AEVs commonly increased with the DSAS insole.

CONCLUSIONS

Dr. Scholl's Active Series insoles demonstrate efficacy in reducing VLRs, which are associated with plantar fasciitis. Biomechanical changes to variables associated with tibial stress syndrome (AEVs, AEAs) and patellofemoral pain syndrome (KAAIs) were inconsistent.

Hard, soft and off-the-shelf foot orthoses and their effect on the angle of the medial longitudinal arch: A biplane fluoroscopy study

BACKGROUND

Foot orthoses have proven to be effective for conservative management of various pathologies. Pathologies of the lower limb can be caused by abnormal biomechanics such as irregular foot structure and alignment, leading to inadequate support.

OBJECTIVES

To compare biomechanical effects of different foot orthoses on the medial longitudinal arch during dynamic gait using skeletal kinematics.

STUDY DESIGN

This study follows a prospective, cross-sectional study design.

METHODS

The medial longitudinal arch angle was measured for 12 participants among three groups: pes planus, pes cavus and normal arch. Five conditions were compared: three orthotic devices (hard custom foot orthosis, soft custom foot orthosis and off-the-shelf Barefoot Science©), barefoot and shod. An innovative method, markerless fluoroscopic radiostereometric analysis, was used to measure the medial longitudinal arch angle.

RESULTS

Mean medial longitudinal arch angles for both custom foot orthosis conditions were significantly different from the barefoot and shod conditions ( p < 0.05). There was no significant difference between the off-the-shelf device and the barefoot or shod conditions ( p > 0.05). In addition, the differences between hard and soft custom foot orthoses were not statistically significant. All foot types showed a medial longitudinal arch angle decrease with both the hard and soft custom foot orthoses.

CONCLUSION

These results suggest that custom foot orthoses can reduce motion of the medial longitudinal arch for a range of foot types during dynamic gait.

LEVEL OF EVIDENCE

Therapeutic study, Level 2.

CLINICAL RELEVANCE

Custom foot orthoses support and alter the position of the foot during weightbearing. The goal is to eliminate compensation of the foot for a structural deformity or malalignment and redistribute abnormal plantar pressures. By optimizing the position of the foot, the medial longitudinal arch (MLA) will also change and quantifying this change is of interest to clinicians.