Orthotic Insoles Improve Gait Symmetry and Reduce Immediate Pain in Subjects With Mild Leg Length Discrepancy

Validity of leg length measurement in the supine and standing position compared with pelvic survey X-ray after total hip arthroplasty

INTRODUCTION

The correct adjustment of leg length is a major goal in the implantation of total hip replacements (THRs). Differences in leg length can lead to functional impairment and patient dissatisfaction. By determining leg length at an early stage, before the patient is discharged from hospital, compensatory measures such as the production of special insoles or orthopaedic footwear can be initiated promptly if there is a difference in leg length. Due to shortening of the period of time spent in hospital, the traditional measurement of leg length in a standing position may be increasingly subject to error. A protective posture immediately after surgery or the presence of a twisted pelvis, for example, due to scoliotic spinal misalignments, falsifies the measurement result in the standing position. Here, the measurement of leg length in the supine position may prove to be accurate immediately postoperatively, regardless of potential sources of error, and is to be compared with measurement in the standing position versus radiological measurement on the AP pelvic survey.

MATERIAL AND METHODS

The present retrospective study included 190 patients who had undergone primary total hip arthroplasty. The leg length difference (LLD) of the patients was determined pre- and postoperatively both in the supine and standing position and compared with the postoperative radiological pelvic survey image.

RESULTS

Postoperatively, it was shown that the mean length measured was 0.35 mm too long in the supine position and 0.68 mm too short in the standing position (p value < 0.001). Determination of the average absolute measurement error produces a deviation of 4.06 mm in the standing and 4.51 mm in the supine position (p value 0.126).

CONCLUSIONS

It is shown that the postoperative measurement of LLD in the supine and standing position is equally valid and sufficiently accurate, compared with the gold standard of measurement on a radiograph.

Effects of Artificially Induced Leg Length Discrepancy on Treadmill-Based Walking and Running Symmetry in Healthy College Students: A Lab-Based Experimental Study

Leg length discrepancy (LLD) is a common postural deviation of musculoskeletal origin, which causes compensatory reactions and often leads to injury. The aim of the study was to investigate the effect of artificially induced LLD on gait symmetry by means of the spatiotemporal gait parameters and ground reaction forces (GRFs) using a treadmill equipped with capacitive sensors (instrumented) as well as the EMG activity of trunk and hip muscles during walking and running. Twenty-six healthy male and female college students were required to perform two sets of four 2.5-min walking and running trials on an instrumented treadmill at 5.6 and 8.1 km·h-1, respectively, without (0) and with 1, 2, and 3 cm LLD implemented by wearing a special rubber shoe. Statistical analysis was performed using one-way repeated measures or a mixed-design ANOVA. Most spatiotemporal gait parameters and GRFs demonstrated an increase or decrease as LLD increased either on the short-limb or the long-limb side, with changes becoming more apparent at ≥1 cm LLD during walking and ≥2 cm LLD during running. The EMG activity of trunk and hip muscles was not affected by LLD. Our findings showed that gait symmetry in terms of treadmill-based spatiotemporal parameters of gait and GRFs is affected by LLD, the magnitude of which depends on the speed of locomotion.

Impact of bilateral motion control shoes with outsole adjustment on gait asymmetry in individuals with mild leg length discrepancy

BACKGROUND

Footwear adjustment is recommended in the management plan of leg length discrepancy. However, it is not clear how the outsole of motion control shoe adjustment influences trunk symmetry and walking performance.

RESEARCH QUESTION

Does bilateral adjustment of the outsole affect trunk and pelvis symmetry and ground reaction force during walking in individuals with leg length discrepancy?

METHODS

20 mild leg length discrepancy participants were recruited into a cross-sectional study. All subjects performed a walking trial with their habitual shoes to determine the outsole adjustment. Four trials of walking were carried out in the order of unadjusted and bilateral adjusted motion control air-cushion shoes. Shoulder level differences and trunk and pelvic motion were assessed, while the ground reaction force at the heel strike was reported. A paired t-test was performed to compare the differences between the conditions with a significance level at p < 0.05.

RESULTS

During walking trials, mild leg length discrepancy participants with the adjusted shoe displayed lower variations in the maximum shoulder height differences (p = 0.001) and trunk rotation angle (p = 0.002) than those with the unadjusted shoe. Also, there was a significant reduction in the vertical ground reaction force (p = 0.030), but not in the anteroposterior or mediolateral directions, during walking in the adjusted shoe condition compared to the unadjusted shoe condition.

SIGNIFICANCE

The outsole adjustment of the bilateral motion control shoes can improve trunk symmetry while decreasing the ground impact at the heel strike. The study provides additional information to prescribe or recommend footwear adjustment to improve walking symmetry in leg length discrepancy participants.

Effects of orthotic insole on gait patterns in children with mild leg length discrepancy

BACKGROUND

Leg length discrepancy (LLD) is commonly associated with compensatory gait strategies leading to musculoskeletal disorders of the lower extremity and lumbar spine. Orthotic insole (OI) is considered as a conservative treatment for patients with mild LLD, especially for children. However, the restoration of normal gait when wearing OI with foot lift are still poorly understood.

RESEARCH QUESTION

What are the immediate effects of OI on the gait patterns in children with mild LLD?

METHODS

Gait data and plantar pressure data were collected for 12 children with mild anatomical LLD in barefoot and OI conditions. Paired t-test was performed to determine the changes in gait between these two conditions, and also the symmetry between limbs in the same condition for spatiotemporal, kinematic, and kinetic variables.

RESULTS

Children with mild LLD showed an immediate gait improvement confirmed by increased step length and velocity, decreased peak plantar pressure in both limbs with OI. Additionally, the significant between-limb differences disappeared for peak ankle dorsiflexion, hip adduction, pelvis upward obliquity and also second peak plantar pressure with OI, which improved gait symmetry.

SIGNIFICANCE

This study provides a better understanding of the immediate effect of OI with foot lift on biomechanical changes in gait, which identify that OI with foot lift could be a potential therapeutic option for children with mild structural LLD to improve gait metrics.

Leg Length Discrepancy and Nonspecific Low Back Pain: 3-D Stereophotogrammetric Quantitative Posture Evaluation Confirms Positive Effects of Customized Heel-Lift Orthotics

Background: The literature reports evidence of leg length discrepancy (LLD) associated with musculoskeletal disorders, alterations in spinopelvic alignment, and body posture, leading to low back pain and lumbar scoliosis. The most common conservative treatment for LLD is the use of internal or external shoe lifts although no treatment guidelines have been established.

Aim: The study aimed to contribute to low back pain–LLD relationship comprehension, highlighting the benefits of LLD correction in the nonspecific low back pain (NSLBP) population.

Methods: A cross-sectional observational study recruited a cohort of 80 NSLBP patients (48 females, 32 males) with LLD, age (μ = 35 ± 17.2). Entire body posture, including 3-D spine shape reconstruction, was measured using a nonionizing 3-D optoelectronic stereophotogrammetric approach. After the first 3-D posture evaluation, patients were provided with customized orthotics, including 100% LLD heel lift correction. No other therapeutic interventions were considered. Pain level was assessed using the numerical pain rating scale (NPRS). The gender, age-related, and time-dependent effects of LLD equalization treatment in NSLBP patients was investigated during 2 years of follow-up. The statistical analysis was performed at the global level using multivariate methods by Hotelling T² tests and intrasubject-level using t-test.

Results and Discussion: An initial average NPRS = 7.8 was determined. In the medium-term follow-up group (4 months), the NPRS dramatically decreased (NPRS = 1.1). The pain disappeared in the long-term (2 years) follow-up group (NPRS = 0). The study results highlight that LLD equalization treatment led to clear statistically significant improvements in all the postural parameters of the frontal plane, including the underfoot load asymmetry. No worsening has been detected. An adaptation period long enough is needed to obtain progressive pain relief improvements and structural posture changes. Younger NSLBP patients showed slightly better improvements than older ones. Minimal differences between healthy young adults’ and NSLBP patients’ postures were found either in natural erect standing posture or when LLD equalization is applied.

Conclusion: Heel-lift customized orthotics with 100% LLD correction are an effective short- and long-term treatment in patients with nonspecific LBP, inducing pain symptom recession and stimulating the improvement of postural parameters without contraindications.

High-risk factors for subjective discomfort due to lower limb discrepancy after medial open wedge high tibial osteotomy

BACKGROUND

Medial open wedge high tibial osteotomy (OWHTO) may result in lower limb discrepancy (LLD), and some patients experience uncomfortable symptoms. Studies have found that the degree of LLD is one but not the only high-risk factor for inducing symptoms. The main purpose of this study is to explore the risk factors for symptomatic LLD.

METHODS

Sixty-four patients who underwent OWHTO in our hospital between June 2018 and January 2020 were included in the study. Changes in tibia length, lower limb length, femorotibial angle (FTA), LLD, and KOOS score were evaluated before and 1 year after surgery. Questionnaire was used to investigate whether patients had uncomfortable symptoms of LLD after surgery. Binary logistic regression was applied to analyze the risk factors of symptomatic LLD.

RESULTS

There were 18 patients with subjective LLD uncomfortableness, 13 of them were occasional and 5 were frequent. Patients had a mean correction angle of 11.7° ± 4.6°, with a mean increase in tibial length of 6.0 ± 3.5 mm, lower limb length of 7.5 ± 2.3 mm, and LLD of 6.9 ± 4.2 mm at 1 year post-operation. Preoperative and postoperative changes in tibia length and lower limb length were statistically significant (P < 0.0001).There were statistically significant differences in pain, symptoms, ADL, sports/recreations, QOL of KOOS subclassification before and after surgery (P < 0.0001). Binary logistic regression revealed that age ≥ 55, BMI ≥ 28, and LLD ≥ 10 mm were high-risk factors for symptomatic LLD (P = 0.031, OR = 4.82; P = 0.012, OR = 6.251; P = 0.006, OR = 6.836).

CONCLUSION

Patients with age ≥ 55, BMI ≥ 28, and postoperative LLD ≥ 10 mm are more likely to develop symptomatic LLD. Older or heavier patients, who are expected to have an LLD greater than 10 mm after OWHTO should be fully informed of the possibility of postoperative LLD symptoms.