The effects of leg length discrepancy on gait and balance

Leg length discrepancy is a condition shown to affect 25-70% of the general population. The ubiquitous nature of leg length discrepancy can prove frustrating to many clinicians, particularly due to lack of consensus surrounding the amount of discrepancy that necessitates treatment. The present research is intended to address the uncertainty surrounding diagnostic and treatment thresholds, through three related studies. In the first study, leg length discrepancy was manipulated in a sample of 15 healthy young adults, using a novel heel-to-toe lift (creating discrepancies of 5mm, 20mm, and 30mm), and the effects of this new discrepancy was observed on the spatial-temporal parameters of gait. In the second study, leg length discrepancy was again manipulated (within a sample of 40 healthy young adults) in a similar fashion to the first study, and the effects of this discrepancy on both gait and balance were observed within a dual-task paradigm, wherein attentional capacity was manipulated using an ecologically valid secondary task (dialling numbers on a cellphone). Finally, in the third study, long-term gait adaptation was measured within a sample of 100 individuals (aged 25 to 76) that had undergone an high tibial osteotomy, and who had a surgically induced leg length discrepancy from this operation. This study used leg length discrepancy as a covariate in the model, to control for the extent to which post-surgical gait changes were the result of leg length discrepancy. Taken together, the results of these three studies provide several important pieces of clinical information: (1) small discrepancies (as small as 5mm) can disrupt gait; (2) larger discrepancies (particularly when they are qualitatively obvious to the individual) may require conscious attention to the gait adaptation; (3) conscious gait adaptation may be be disrupted by attention-demanding secondary tasks; and (4) the effects of acquired leg-length discrepancy persist for as long as a year after they are induced. These results are presented in the context of a “leg length accommodation model”, that incorporates perceptual aspects of the leg length discrepancy, and attentional capacity (for the accommodation of the discrepancy)

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 abnormal foot structure and alignment, leading to inadequate support. Objectives: To compare biomechanical effects of different foot orthoses on the medial longitudinal arch (MLA) during dynamic gait using skeletal kinematics. Study Design: Prospective, cross-sectional study design. Methods: The MLA 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 (CFO), soft CFO, and off-the-shelf Barefoot Science©), barefoot and shod. An innovative method, markerless fluoroscopic radiostereometric analysis (RSA), was used to measure the MLA angle. Results: Mean MLA angles for both CFO conditions were significantly different from the barefoot and shod conditions (p0.05). Additionally, the differences between hard and soft CFOs were not statistically significant. All foot types showed an MLA angle decrease with both the hard and soft CFOs. Conclusions: These results suggest that CFOs can reduce motion of the MLA for a range of foot types during dynamic gait

Reliability of a multi-segment foot model in a neutral cushioning shoe during treadmill walking

Abstract Background Detailed kinematics of the foot has been frequently reported on in the literature, specifically using various multi-segment foot models. It is important to identify the reliability of a multi-segment foot model in a population of mixed genders and activity levels, while walking in commonly used footwear. The main objective of this study was to investigate the between-day reliability and within-session variability of the Oxford Foot Model (OFM) while walking in a neutral cushioning shoe. Methods A 7-camera Vicon motion capture system was used along with 29 passive reflective markers, placed on the participant to examine the multi-segment foot kinematics of the left foot using the OFM. Windows were cut in New Balance 840 shoes following reports from a previous investigation to maintain shoe integrity during testing. Two walking sessions on separate days were collected for 12 healthy participants, with an average total of 22 gait cycles per day. Results ICCs ranged from 0.020 to 0.964 for between-day reliability, and within-session ICC values ranged from 0.268 to 0.985. Between-day ICC values of the relative measures (excursion and range of motion (ROM)) were higher than the absolute angle measures (angle at foot strike and peak angle). Largest differences were measured in the transverse plane, and the smallest differences in the sagittal plane. Bland-Altman plots revealed best agreement in the frontal and sagittal planes. SEM values ranged from 0.04 to 3.5 for the between-day reliability. Conclusions Between-day reliability and within-session variability were comparable to previous studies for adults walking barefoot and shod. This research demonstrates that the OFM can produce reliable data when applied to the assessment of a shod foot

Medial Longitudinal Arch Angle Presents Significant Differences between Foot Types: A Biplane Fluoroscopy Study

© Copyright 2016 by ASME. The structure of the medial longitudinal arch (MLA) affects the foot\u27s overall function and its ability to dissipate plantar pressure forces. Previous research on the MLA includes measuring the calcaneal-first metatarsal angle using a static sagittal plane radiograph, a dynamic height-to-length ratio using marker clusters with a multisegment foot model, and a contained angle using single point markers with a multisegment foot model. The objective of this study was to use biplane fluoroscopy to measure a contained MLA angle between foot types: pes planus (low arch), pes cavus (high arch), and normal arch. Fifteen participants completed the study, five from each foot type. Markerless fluoroscopic radiostereometric analysis (fRSA) was used with a three-dimensional model of the foot bones and manually matching those bones to a pair of two-dimensional radiographic images during midstance of gait. Statistically significant differences were found between barefoot arch angles of the normal and pes cavus foot types (p=0.036), as well as between the pes cavus and pes planus foot types (p=0.004). Dynamic walking also resulted in a statistically significant finding compared to the static standing trials (p=0.014). These results support the classification of individuals following a physical assessment by a foot specialist for those with pes cavus and planus foot types. The differences between static and dynamic kinematic measurements were also supported using this novel method