Youichi Shimada

A diagnostic support tool for lumbar spinal stenosis: a self-administered, self-reported history questionnaire

BackgroundThere is no validated gold-standard diagnostic support tool for LSS, and therefore an accurate diagnosis depends on clinical assessment. Assessment of the diagnostic value of the history of the patient requires an evaluation of the differences and overlap of symptoms of the radicular and cauda equina types; however, no tool is available for evaluation of the LSS category. We attempted to develop a self-administered, self-reported history questionnaire as a diagnostic support tool for LSS using a clinical epidemiological approach. The aim of the present study was to use this tool to assess the diagnostic value of the history of the patient for categorization of LSS.MethodsThe initial derivation study included 137 patients with LSS and 97 with lumbar disc herniation who successfully recovered following surgical treatment. The LSS patients were categorized into radicular and cauda equina types based on history, physical examinations, and MRI. Predictive factors for overlapping symptoms between the two types and for cauda equina symptoms in LSS were derived by univariate analysis. A self-administered, self-reported history questionnaire (SSHQ) was developed based on these findings. A prospective derivation study was then performed in a series of 115 patients with LSS who completed the SSHQ before surgery. All these patients recovered following surgical treatment. The sensitivity of the SSHQ was calculated and clinical prediction rules for LSS were developed. A validation study was subsequently performed on 250 outpatients who complained of lower back pain with or without leg symptoms. The sensitivity and specificity of the SSHQ were calculated, and the test-retest reliability over two weeks was investigated in 217 patients whose symptoms remained unchanged.ResultsThe key predictive factors for overlapping symptoms between the two categories of LSS were age > 50, lower-extremity pain or numbness, increased pain when walking, increased pain when standing, and relief of symptoms on bending forward (odds ratio ≥ 2, p < 0.05). The key predictive factors for cauda equina type symptoms were numbness around the buttocks, walking almost causes urination, a burning sensation around the buttocks, numbness in the soles of both feet, numbness in both legs, and numbness without pain (odds ratio ≥ 2, p < 0.05). The sensitivity and specificity of the SSHQ were 84% and 78%, respectively, in the validation data set. The area under the receiver operating characteristic curve was 0.797 in the derivation set and 0.782 in the validation data set. In the test-retest analysis, the intraclass correlation coefficient for the first and second tests was 85%.ConclusionA new self-administered, self-reported history questionnaire was developed successfully as a diagnostic support tool for LSS.

Biomechanical analysis and muscle tension estimation of the lower extremities using EMG data

Functional electrical stimulation (FES) rowing is a whole-body exercise in which the lower extremities are moved by electric stimulation and the upper extremities are moved voluntarily by paraplegics. The purpose of this study was to identify the kinematic factors of the lower extremities required to perform FES-rowing through the biomechanical analysis. Eighteen healthy adult men participated in this study. A mathematical model was developed to analyze the conventional rowing with or without handle and FES lower extremity extension exercise. The calculated data has the potential to be applied in the low-load and safe FES rowing exercise for the paraplegics.

Biomechanical analysis for FES assisted swing-through gait

Swing-through gait is a method of providing paraplegic patients a faster means of mobility. The purpose of this study was to analyze the kinematics of body extremities during swing-through crutches gait with free-knees. Twelve non-disabled adult males participated in this study. Joint angles and ground reaction forces were investigated during the swing-through gait with crutches. A mathematical model consisting of linked rigid bodies was developed to analyze the gait, and the joint moments of lower extremities were calculated. The swing-through gait using Functional Electrical Stimulation (FES) with crutches has a problem that patients upper limbs have to support their body against gravity during the body-swing phase. So we compared the energy consumption in upper limb muscles during the swing-through gait using axillary and elbow crutches to consider the selection of a suitable crutch for the swing-through gait by FES. The energy consumption in pectoralis major, biceps and brachialis using the axillary crutch was significantly larger than the gait using the elbow crutch. The energy consumption in the middle part of the deltoid, and long and short heads of the triceps using the elbow crutch was significantly larger than the axillary crutch walking. But there was no significant difference in the total energy consumption between the crutches. The calculated data has the potential to be applied in the clinical restoration for the swing-through gait in complete paraplegics with free-knees.