Slower gait speed, cadence and longer gait cycle time were seen in patients with sporadic inclusion body myositis, according to newly published data.
A sample of 42 patients with sporadic inclusion body myositis (s-IBM) was assessed for gait alterations compared with results from prior studies of healthy, age-matched adults. Diagnosis of s-IBM was confirmed with muscle biopsy in patients with mean age of 61.8 years, only 12 of whom were women. Patients were excluded if cardiovascular or renal diseases were present or if muscular impairment or joint instability precluded regular travel. Nineteen participants used a gait aid such as a cane or walker during the assessment.
Patients’ gait characteristics were assessed using a portable stride analyzer, and muscle maximum voluntary isometric contraction (MVIC) was assessed using a quantitative muscle testing system. Included muscle groups were hip and knee extensors and hip, knee and ankle plantar flexors. Participants were instructed to perform two walking trials at their normal speed and two trials walking as fast as possible across the stride analyzer and were divided into high-force or low-force groups based on the results.
Knee and hip extensors demonstrated the most relative weakness compared with prior studies the authors used as predictive norms. MVIC values in knee extensors were 14.9% of predicted values and 23.8% in hip extensors. Hip flexors were 32% and plantar flexors were 31.8% of predicted values. Overall, the values of all muscle groups was 27% of the reference values predicted, according to the researchers.
During both normal and fast walking speeds, patients with s-IBM had longer gait cycle time, slower gait speed and decreased cadence compared to reference values, and was not associated with age, sex, disease duration or age of disease onset. A significant but moderate association between MVIC values and temporal gait variables was also seen, and ankle plantar and knee flexors were most strongly associated with walking performance.
The high-force group had significantly lower BMI and better gait variables compared with the low-force group, particularly gait cycle time. – by Shirley Pulawski
Disclosure: The authors have no relevant financial disclosures.