A Pilot Study of Factors Associated With Falls in Individuals With Incomplete Spinal Cord Injury

Abstract

Background/Objective: To determine factors associated with falls among a sample of ambulatory individuals with incomplete spinal cord injury (SCI).

Study Design: Cross-sectional mail survey.

Methods: A survey instrument of participant characteristics and fall-related variables was developed using relevant items from existing measures and was mailed to 221 individuals with incomplete SCI, who were identified from records of a large specialty hospital in the southeastern United States. Of the 221 prospective participants, 119 completed the questionnaire (54%). Multivariable logistic regression models were used to determine factors that were independently associated with having had a fall in the past year.

Results: After adjusting for covariates, having fallen in the past year was significantly (P < 0.05) associated with greater numbers of medical conditions (odds ratio [OR] = 1.3; 95% confidence interval [Cl] = 1.0-1.7), having arthritis (OR = 3.4, 95% Cl = 1.2-9.6), experiencing dizziness (OR = 5.6, 95% Cl = 1.1-27.7), greater numbers of days with poor physical health (OR = 1.1; 95% Cl = 1.0-1.3), and the restriction of community activities because of fear of falling (OR = 1.5, 95% Cl = 1.1-2.1). The multivariable models also showed that the odds of having fallen were significantly lower among those with better current perceived physical health (OR = 0.5; 95% Cl = 0.3-0.9), those with better perceived health compared to a year ago (OR = 0.4; 95% Cl = 0.2-0.8), individuals who exercised more frequently (OR = 0.2; 95% Cl = 0.1-0.7), and those who used a walker (OR = 0.3; 95% CI = 0.1-0.9).

Conclusions: Results suggest that interventions that address exercise frequency, walker use, and dizziness have promise for reducing falls for individuals with incomplete SCI.     

Locomotor Training and Muscle Function After Incomplete Spinal Cord Injury: Case Series

Abstract

Background/Objective: To determine whether 9 weeks of locomotor training (LT) results in changes in muscle strength and alterations in muscle size and activation after chronic incomplete spinal cord injury (SCI). Study Design: Longitudinal prospective case series.

Methods: Five individuals with chronic incomplete SCI completed 9 weeks of LT. Peak isometric torque, torque developed within the initial 200 milliseconds of contraction (Torque₂₀₀), average rate of torque development (ARTD), and voluntary activation deficits were determined using isokinetic dynamometry for the knee-extensor (KE) and plantar-flexor (PF) muscle groups before and after LT. Maximum muscle crosssectional area (CSA) was measured prior to and after LT.

Results: Locomotor training resulted in improved peak torque production in all participants, with the largest increases in the more-involved PF (43.9% ± 20.0%), followed by the more-involved KE (21.1% ± 12.3%). Even larger improvements were realized in Torque200 and ARTD (indices of explosive torque), after LT. In particular, the largest improvements were realized in the Torque200 measures of the PF muscle group. Improvements in torque production were associated with enhanced voluntary activation in both the KE and ankle PF muscles and an increase in the maximal CSA of the ankle PF muscles.

Conclusion: Nine weeks of LT resulted in positive alterations in the KE and PF muscle groups that included an increase in muscle size, improved voluntary activation, and an improved ability to generate both peak and explosive torque about the knee and ankle joints.     

Outcomes of a Home Cycling Program Using Functional Electrical Stimulation or Passive Motion for Children With Spinal Cord Injury: A Case Series

Abstract

Background/Objective: Children with spinal cord injury (SCI) are at risk for musculoskeletal and cardiovascular complications. Stationary cycling using functional electrical stimulation (FES) or passive motion has been suggested to address these complications. The purpose of this case series is to report the outcomes of a 6-month at-home cycling program for 4 children with SCI.

Methods: Two children cycled with FES and 2 cycled passively at home for 1 hour, 3 times per week.

Outcome Measures: Data collected included bone mineral density of the left femoral neck, distal femur, and proximaltibia; quadriceps and hamstring muscle volume; stimulated quadriceps and hamstring muscle strength; a fasting lipid profile; and heart rate and oxygen consumption during incremental upper extremity ergometry testing.

Results: The 2 children cycling with FES and 1 child cycling passively exhibited improved bone mineral density, muscle volume, stimulated quadriceps strength, and lower resting heart rate. For the second child cycling passively, few changes were realized. Overall, the lipid results were inconsistent, with some positive and some negative changes seen.

Conclusions: This case series suggests that cycling with or without FES may have positive health benefits and was a practical home exercise option for these children with SCI.     

A Spectral Analysis of Rotator Cuff Musculature Electromyographic Activity: Surface and Indwelling

Electromyography (EMG) of the shoulder girdle is commonly performed; however, EMG spectral properties of shoulder muscles have not been clearly defined. The purpose of this study was to determine the maximum power frequency, Nyquist rate, and minimum sampling rate for indwelling and surface EMG of the normal shoulder girdle musculature. EMG signals were recorded using indwelling electrodes for the rotator cuff muscles and surface electrodes for ten additional shoulder muscles in ten healthy volunteers. A fast Fourier transform was performed on the raw EMG signal collected during maximal isometric contractions to derive the power spectral density. The 95% power frequency was calculated during the ramp and plateau subphase of each contraction. Data were analyzed with analysis of variance (ANOVA) and paired t tests. Indwelling EMG signals had more than twice the frequency content of surface EMG signals (p < .001). Mean 95% power frequencies ranged from 495 to 560 Hz for indwelling electrodes and from 152 to 260 Hz for surface electrodes. Significant differences in the mean 95% power frequencies existed among muscles monitored with surface electrodes (p = .002), but not among muscles monitored with indwelling electrodes (p = .961). No significant differences in the 95% power frequencies existed among contraction subphases for any of the muscle–electrode combinations. Maximum Nyquist rate was 893 Hz for surface electrodes and 1,764 Hz for indwelling electrodes. Our results suggest that when recording EMG of shoulder muscles, the minimum sampling frequency is 1,340 Hz for surface electrodes and 2,650 Hz for indwelling electrodes. The minimum sampling recommendations are higher than the 1,000 Hz reported in many studies involving EMG of the shoulder.     

Functional exercise capacity evaluated by timed walk tests in myasthenia gravis

Introduction: We sought to evaluate the test–retest reliability and construct validity of the 6- and 2-minute walk tests (6mWT and 2mWT, respectively) in patients with myasthenia gravis (MG). Methods: Thirty-one patients with generalized MG were enrolled in this study. The 6mWT, 2mWT, MG-specific quality of life questionnaire Turkish version (MG-QoL15T), quantitative myasthenia gravis test (QMG), and pulmonary function tests were administered. Results: The intraclass correlation coefficients of 2mWT and 6mWT were 0.894 and 0.932, respectively. The 6mWT and 2mWT had moderate correlations with forced vital capacity, maximal inspiratory pressure, QMG score, and MG-QoL15T score (ρ for 6mWT: 0.579, 0.539, −0.572, and −0.474; ρ for 2mWT: 0.460, 0.446, −0.532, −0.457). Both tests had similar performances for predicting disease severity (area under the curve = 0.761 for 6mWT and 0.759 for 2mWT). Discussion: The 6mWT and 2mWT have excellent test–retest reliability as well as moderate construct validity for the evaluation of functional exercise capacity patients with MG. Muscle Nerve 59 :208–212, 2019     

Collagen XII myopathy with rectus femoris atrophy and collagen XII retention in fibroblasts

Introduction: Mutation in the collagen XII gene (COL12A1) was recently reported to induce Bethlem myopathy. We describe a family affected by collagen XII‐related myopathy in 3 generations. Methods: Systematic interview, clinical examination, skin biopsies, and MRI of muscle were used. Results: The phenotype was characterized by neonatal hypotonia, contractures, and delayed motor development followed by resolution of contractures and a motor performance limited by reduced endurance. DNA analyses revealed a novel donor splice‐site mutation in COL12A1 (c.8100 + 2T>C), which segregated with clinical affection and abnormal collagen XII retention in fibroblasts. MRI disclosed a selective wasting of the rectus femoris muscle. Discussion: COL12A1 mutations should be considered in patients with a mild Bethlem phenotype who present with selective wasting of the rectus femoris, absence of the outside‐in phenomenon on MRI, and abnormal collagen XII retention in fibroblasts. Muscle Nerve 57 : 1026–1030, 2018