Analysis of Dynamic Plantar Pressure before and after the Occurrence of Neurogenic Intermittent Claudication in Patients with Lumbar Spinal Stenosis: An Observational Study

Foot pressure transfers are altered in lumbar radiculopathy but reversible after surgery: a prospective, pedobarography study

BACKGROUND CONTEXT

Patients with lower lumbar stenosis and disc herniation report disability in standing and ambulation, despite normal neurological examination. The L5 and S1 nerve roots support the entire motor and sensory function of the foot, and their radiculopathy can affect foot loading during standing and walking. This has not been quantified before.

PURPOSE

To quantify alterations in static and dynamic foot pressure transfers in patients with lower lumbar nerve root compression, and document any beneficial effects of surgical decompression.

STUDY DESIGN

Prospective, case-control study.

PATIENT SAMPLE

Cases-Patients with unilateral radiculopathy (L5/S1) with normal neurology (n=50); Controls - Healthy volunteers (n=50).

METHODS

The volunteers and patients underwent pedobarographic analysis during standing (static) and walking (dynamic), and fifteen (12 dynamic and three static) parameters were documented. The patient's preoperative values were compared with that of the healthy volunteers. All the 50 patients underwent surgical decompression, and clinical outcome measures (VAS/ODI at 3 months) were documented. Pedobarographic analysis was repeated in the postoperative period (48 hours) and 3-month follow-up and compared with the preoperative scores.

RESULTS

In healthy controls, the mean values of all 15 parameters were comparable between the right and the left side (p>.05). When compared to controls, the patients had significantly lower maximum foot loads (p=.01) and average foot loads (p=.05) on the affected side during walking indicating lesser load transmission, in the preoperative period. Within the affected foot, the load transfer was higher on the first metatarsal/ medial arch while significantly less on the lateral metatarsals (p=.04). The percentage load on whole foot and forefoot was significantly less on standing (p=.01). Significant improvements were noted in the postoperative period, especially in the maximum foot surface area (p=.01), maximum and average foot loads, and improved weight transfers on lateral arch and forefoot (p=.02). The load on whole foot increased significantly from 46.1%±5.5% (preoperative) to 48.1%±5.5% (postoperative) and 49.9%±3.3% at follow-up (p=.01).

CONCLUSION

This is the first study using pedobarography to document altered foot pressure patterns during ambulation in patients with disc herniation and stenosis. Decreased load transfer, asymmetrical and unphysiological distribution of pressures on the affected foot were observed during weight bearing, which improved after surgical decompression.

Green preparation of antibacterial shape memory foam based on bamboo cellulose nanofibril and waterborne polyurethane for adaptive relief of plantar pressure

This study developed an aqueous solution blending and freeze-drying method to prepare an antibacterial shape memory foam (WPPU/CNF) based on waterborne PHMG-polyurethane and cellulose nanofibers derived from bamboo in response to the increasing demand for environmentally friendly, energy conserving, and multifunctional foams. The obtained WPPU/CNF composite foam has a highly porous network structure with well-dispersed CNFs forming hydrogen bonds with the WPPU matrix, which results in a stable and rigid cell skeleton with enhanced mechanical properties (80 KPa) and anti-abrasion ability. The presence of guanidine in the polyurethane chain endowed the WPPU/CNF composite foam with an instinctive and sustained antibacterial ability against Escherichia coli and Staphylococcus aureus. The WPPU/CNF composite foam exhibited a water-sensitive shape memory function in a cyclic shape memory program because of the chemomechanical adaptability of the hydrogen-bonded network of CNFs in the elastomer matrix. The shape-fixation ratio for local compression reached 95 %, and the shape-recovery rate reached 100 %. This allows the WPPU/CNF pad prototype to reversibly adjust the undulation height to adapt to plantar ulcers, which can reduce the local plantar pressure by 60 %. This study provides an environmentally friendly strategy for cellulose-based composite fabrication and enriches the design and application of intelligent foam devices.

Gait analysis using digital biomarkers including smart shoes in lumbar spinal canal stenosis: a scoping review

Lumbar spinal canal stenosis (LSS) is characterized by gait abnormalities, and objective quantitative gait analysis is useful for diagnosis and treatment. This review aimed to provide a review of objective quantitative gait analysis in LSS and note the current status and potential of smart shoes in diagnosing and treating LSS. The characteristics of gait deterioration in LSS include decreased gait velocity and asymmetry due to neuropathy (muscle weakness and pain) in the lower extremities. Previous laboratory objective and quantitative gait analyses mainly comprised marker-based three-dimensional motion analysis and ground reaction force. However, workforce, time, and costs pose some challenges. Recent developments in wearable sensor technology and markerless motion analysis systems have made gait analysis faster, easier, and less expensive outside the laboratory. Smart shoes can provide more accurate gait information than other wearable sensors. As only a few reports exist on gait disorders in patients with LSS, future studies should focus on the accuracy and cost-effectiveness of gait analysis using smart shoes.

Comparison of the plantar pressure distribution and mechanical alignment in patients with varus knee osteoarthritis following high tibial osteotomy

PURPOSE

The changes in the lower limb alignment were vitally important after high tibial osteotomy (HTO). Therefore, the purpose of present study was to analyze the characteristics of plantar pressure distribution after HTO, and to investigate the effect of plantar pressure distribution on postoperative limb alignment.

METHODS

Between May 2020 and April 2021, varus knee patients undergoing HTO were evaluated in the present study. The peak pressure of plantar regions, medial-lateral pressure ratio (MLPR), foot progression angle (FTA), anteroposterior COP (AP-COP), lateral symmetry of COP (LS-COP), and the radiographic parameters were evaluated preoperatively and at the final follow-up. Compared among the slight valgus (SV), moderate valgus (MV) and large valgus (LV) groups at the final follow-up, the peak pressure of HM, HC and M5 regions, and the MLPR were compared; the Knee Injury and Osteoarthritis Outcome Score4 (KOOS4) including four subscales, and the American of orthopedic foot and ankle society (AOFAS) were evaluated.

RESULTS

The WBL%, HKA and TPI angle changed significantly after HTO (P < 0.001). The preoperative group exhibited a lower peak pressure in the HM region (P < 0.05) and higher peak pressure in the M5 region (P < 0.05); the pre- and postoperative groups exhibited a lower peak pressure in the HC region (P < 0.05); the rearfoot MLPR was significantly lower and LS-COP was significantly higher in the preoperative group (P = 0.017 in MLPR and 0.031 in LS-COP, respectively). Comparison among the SV, MV and LV groups, the SV group indicated a lower peak pressure in the HM region (P = 0.036), and a lower MLPR in the rearfoot (P = 0.033). The KOOS Sport/Re score in the MV and LV groups increased significantly compared with the SV group (P = 0.042).

CONCLUSION

Plantar pressure distribution during the stance phase in patients with varus knee OA following HTO exhibited a more medialized rearfoot plantar pressure distribution pattern than that before surgery. Compared with the small valgus alignment, a moderate to large valgus alignment allows patients to walk with a more even medial and lateral plantar pressure distribution, which is more similar to healthy adults.

Objective Evaluation of Neurogenic Intermittent Claudication for Patients With Lumbar Spinal Stenosis Based on Plantar Pressure Analysis

STUDY DESIGN

A cross-sectional study.

OBJECTIVE

To quantify the severity of neurogenic intermittent claudication (NIC) for patients with lumbar spinal stenosis (LSS) based on the center of pressure trajectory.

SUMMARY OF BACKGROUND DATA

NIC is one of the typical symptoms of LSS. So far, the severity level of NIC is mainly evaluated by the subjective description of patients, which might be biased by patients' background differences and thus lead to an ineffective diagnosis or inappropriate treatment for LSS. Therefore, it remains necessary to develop a reliable clinical technique for quantitative evaluation of NIC to achieve more effective therapy for LSS.

MATERIALS AND METHODS

In the present study, the Footscan pressure system was used to detect the center of pressure trajectory. The real-time walking distance (rtWD) and the corresponding displacement of the medial-lateral center of pressure (ML-COP) were calculated based on the trajectory. The differences of ML-COP between LSS and control groups were analyzed using a one-way repeated measures analysis of variance. Regression and Pearson correlation analysis were used to investigate the correlation between rtWD and ML-COP, as well as the relation between the Oxford Claudication Score (OCS) and clinical evaluation indicators.

RESULTS

The present study included 31 LSS patients and 31 healthy controls. There were no significant differences in demographic data between the two groups ( P >0.05). The results indicated that ML-COP would increase with the number of laps in the LSS group while not in the control group. Also, a linear relationship was identified between the ML-COP and rtWD for LSS patients ( R2 >0.80, P <0.05). Since the incremental rate of ML-COP for LSS patients was reflected by the regression coefficients of the linear regression analysis, thus the regression coefficients were defined as the claudication correlation coefficients (CCCs). In addition, it was indicated by the statistical analysis that there was a strong positive correlation between OCS and CCC ( r =0.96; P <0.001) and a medium negative correlation with final walking distance ( r =-0.67; P <0.001). It was also noticed that there was no significant correlation between the average ML-COP and OCS ( r =-0.03; P =0.864).

CONCLUSIONS

The ML-COP of LSS patients would increase with the patients' walking distance. This incremental rate, characterized by the CCC, would be used as an effective indicator to quantify the severity level of the NIC for potentially more accurate and reliable diagnosis, evaluation, and treatment of LSS.

LEVEL OF EVIDENCE

3.

Changes in kinematics, kinetics, and muscle activity in patients with lumbar spinal stenosis during gait: systematic review

BACKGROUND CONTEXT

Lumbar spinal stenosis (LSS) is one of the most common orthopaedic conditions and affects more than half a million people over the age of 65 in the US. Patients with LSS have gait dysfunction and movement deficits due to pain and symptoms caused by compression of the nerve roots within a narrowed spinal canal.

PURPOSE

The purpose of the current systematic review was to summarize existing literature reporting biomechanical changes in gait function that occur with LSS, and identify knowledge gaps that merit future investigation in this important patient population.

STUDY DESIGN/SETTING

This study is a systematic literature review.

OUTCOME MEASURES

The current study included biomechanical variables (e.g., kinematic, kinetic, and muscle activity parameters).

METHODS

Relevant articles were selected through MEDLINE, Scopus, Embase, and Web of Science. Articles were included if they: 1) included participants with LSS or LSS surgery, 2) utilized kinematic, kinetic, or muscle activity variables as the primary outcome measure, 3) evaluated walking or gait tasks, and 4) were written in English.

RESULTS

A total of 11 articles were included in the current systematic review. The patients with LSS exhibited altered gait function as compared to healthy controls. Improvements in some biomechanical variables were found up to one year after surgery, but most gait changes were found within one month after surgery.

CONCLUSIONS

Although numerous studies have investigated gait function in patients with LSS, gait alterations in joint kinetics and muscle activity over time remain largely unknown. In addition, there are limited findings of spinal kinematics in patients with LSS during gait. Thus, future investigations are needed to investigate longer-term gait changes with regard to spinal kinematics, joint kinetics, and muscle activity beyond one month after LSS surgery.