Lower Extremity Peak Force and Gait Kinematics in Individuals With Inclusion Body Myositis

Abstract

Objective. To determine the relationship between peak isometric muscle force and temporal characteristics of gait in individuals with sporadic inclusion body myositis (s-IBM).Methods. An observational study of 42 individuals with s-IBM (12 women; mean ؎ SD age 61.8 ؎ 7.3 years and mean ؎ SD disease duration 8.9 ؎ 4.3 years) was conducted at a federal hospital. Peak isometric force measurements for lower extremity (LE) muscle groups were obtained using quantitative muscle testing. Temporal characteristics of gait during habitual and fast walking conditions were measured using a portable gait analysis system. Results. All observed muscle force values were significantly lower than predicted values (P < 0.001). During habitual walking, the subjects' gait speed and cadence were <83% of normative literature values. During fast walking, total gait cycle time was 133% of normal, while gait speed and cadence were 58% and 78% of normative literature values, respectively. Scaled LE peak muscle forces showed significant moderate correlations with temporal gait variables. Weaker subjects had greater limitations in gait speed and cadence compared with stronger subjects (P < 0.05). Peak isometric force of the knee flexors and ankle plantar flexors was significantly correlated with most temporal features of habitual gait. Conclusion. Muscle weakness associated with s-IBM disease activity may contribute to diminished gait kinematics. Temporal features of gait were not substantially influenced by knee extensor weakness alone, considering the knee flexors and ankle plantar flexors played a compensatory role in maintaining the walking ability of individuals with s-IBM.

The Influence of Upper and Lower Extremity Strength on Performance-Based Sarcopenia Assessment Tests

“…Notably, our older community-dwelling veteran participants (mean age, 62.5 ± 9.2) exhibited hand grip strength that was significantly associated with fast gait speed ( p = 0.02), but not customary gait speed ( p = 0.18). Our previous study of older adults with intrinsic muscle disease demonstrated that individuals may exhibit decrements in strength approaching 50% of normative values, yet still maintain walking speeds that exceed 1.0 m/s [ 44 ]. The redundancy in muscle group contributions to gait, and the role of ground reaction forces during stance phase, may obfuscate early muscle impairments when temporal gait parameters remain stable [ 25 , 44 ].…”

“…Our previous study of older adults with intrinsic muscle disease demonstrated that individuals may exhibit decrements in strength approaching 50% of normative values, yet still maintain walking speeds that exceed 1.0 m/s [ 44 ]. The redundancy in muscle group contributions to gait, and the role of ground reaction forces during stance phase, may obfuscate early muscle impairments when temporal gait parameters remain stable [ 25 , 44 ]. Consequently, more demanding functional tasks, such as the fast walking test [ 25 ], may show a stronger association with local and global measures of strength as shown in this report.…”

Physical function and muscle strength in sporadic inclusion body myositis

“…In sIBM patients, very few studies have addressed the relationship between mechanical muscle function and functional capacity. The use of gait assistive devices has been associated with lower knee extension muscle strength, yet other reports have shown that gait kinematics are related to maximal muscle strength of the hip flexors/extensors, knee flexors/extensors, and plantarflexors . Recent modeling data indicate that maximal muscle strength in hip flexors, plantarflexors, and knee extensors, together with body weight, are important determinants of gait function in sIBM patients, and knee extensor strength and age at disease onset altogether predict the ability to step up onto a curb .…”

Sporadic inclusion body myositis: A review of recent clinical advances and current approaches to diagnosis and treatment

“…Recent studies have looked at the frequency and circumstances of falls (Hiscock et al, 2014), and have analysed the abnormal gait patterns in patients with IBM (Bernhardt et al, 2011, Davenport et al, 2015 finding that there is a good correlation between knee extensor strength and functional lower limb measures such as the 2-minute and 6-minute walk tests (Lowes et al, 2012, Alfano et al, 2014. A smaller group of patients present initially because of weakness of the long finger flexor muscles, which is usually more severe in the non-dominant hand, or bulbar weakness, with lower limb weakness occurring at a later stage.…”