Verena Matschke

Benefits of exercise in Rheumatoid Arthritis.

This paper aims to highlight the importance of exercise in patients with rheumatoid arthritis (RA) and to demonstrate the multitude of beneficial effects that properly designed exercise training has in this population. RA is a chronic, systemic, autoimmune disease characterised by decrements to joint health including joint pain and inflammation, fatigue, increased incidence and progression of cardiovascular disease, and accelerated loss of muscle mass, that is, “rheumatoid cachexia”. These factors contribute to functional limitation, disability, comorbidities, and reduced quality of life. Exercise training for RA patients has been shown to be efficacious in reversing cachexia and substantially improving function without exacerbating disease activity and is likely to reduce cardiovascular risk. Thus, all RA patients should be encouraged to include aerobic and resistance exercise training as part of routine care. Understanding the perceptions of RA patients and health professionals to exercise is key to patients initiating and adhering to effective exercise training.

Muscle Quality, Architecture, and Activation in Cachectic Patients with Rheumatoid Arthritis

Objective. To explore muscle-specific force (force per physiological cross-sectional area, or PCSA) and muscle activation in cachectic patients with rheumatoid arthritis (RA). Methods. In 14 muscle-wasted patients with RA and age and sex matched healthy controls, vastus lateralis (VL) force and voluntary activation capacity were assessed during maximal isometric contractions with electromyography and superimposed electrical stimulations. VL PCSA was determined from ultrasound measures of fiber fascicle length (Lf), pennation angle, and volume, together with assessments of body composition by dual energy x-ray absorptiometry and objective physical function. Results. Although patients with RA had reduced physical function, lower muscle mass, and VL volume relative to controls, there were no differences in muscle-specific force and activation. PCSA, force, and pennation angle tended to be lower in RA, with no differences in Lf. Conclusion. Muscle-specific force and activation are not compromised and thus are unlikely to contribute to reduced function in cachectic patients with RA.

Skeletal muscle properties in rheumatoid arthritis patients.

PURPOSE Disability in patients with rheumatoid arthritis (RA) is a multifactorial process involving various unaccounted factors. Loss of lean body mass plays an important role in impaired physical function, and exercise studies in RA have shown promising results in restoring muscle mass, strength, and function. However, no comprehensive assessment of the muscle characteristics has been undertaken to determine whether qualitative changes in muscle also contribute to RA disability. This study explores the physiological muscle properties of a community-based population with stable RA. METHODS Vastus lateralis (VL) force and physiological cross-sectional area (PCSA), voluntary muscle activation capacity, and contractile properties were assessed in 23 patients with stable RA (age = 60 ± 2 yr (mean ± SEM); 16 women) and age- and sex-matched healthy controls (age = 60 ± 3 yr). Measurements with EMG were obtained during maximal isometric knee extension contractions, with resting and superimposed electrical stimulations. Concentric knee extension contractions were also assessed. Pennation angle and VL volume were measured with ultrasound to determine fiber fascicle length and PCSA. Muscle-specific force was calculated (VL force/VL PCSA). Body composition using dual-energy x-ray absorptiometry and objective physical function were also measured. RESULTS The patients displayed typical features of RA with reduced physical function (P = 0.001-0.09), a trend toward lower appendicular lean mass (P = 0.09) and increased total body fat (P < 0.05) relative to controls. However, there were no differences in specific force, contractile properties, voluntary activation capacity, and contraction velocity (P = 0.41-0.99). VL PCSA was reduced (P < 0.05) with minor architectural changes in patients with RA. CONCLUSIONS Physiological properties of muscle that determine specific force are not compromised in patients with stable RA despite deficits in physical function.

Patellar Tendon Properties and Lower Limb Function in Rheumatoid Arthritis and Ankylosing Spondylitis versus Healthy Controls: A Cross-Sectional Study

Objective. Rheumatoid arthritis (RA) and ankylosing spondylitis (AS) lead to inflammation in tendons and peritendinous tissues, but effects on biomechanical tendon function are unknown. This study investigated patellar tendon (PT) properties in stable, established RA and AS patients. Methods. We compared 18 RA patients (13 women, 59.0 ± 2.8 years, mean ± SEM) with 18 age- and sex-matched healthy controls (58.2 ± 3.2 years), and 12 AS patients (4 women, 52.9 ± 3.4 years) with 12 matched controls (54.5 ± 4.7 years). Assessments with electromyography, isokinetic dynamometry, and ultrasound included quadriceps muscle force and cross-sectional area (CSA), PT stiffness, and PT CSA. Additionally, measures of physical function and disease activity were performed. Results. PT stiffness and physical function were lower in RA and AS patients compared to healthy controls, without a significant difference in force production. PT CSA was significantly larger leading to reduction in Youngs modulus (YM) in AS, but not in RA. Conclusion. The adverse changes in PT properties in RA and AS may contribute to their impaired physical function. AS, but not RA, leads to PT thickening without increasing PT stiffness, suggesting that PT thickening in AS is a disorganised repair process. Longitudinal studies need to investigate the time course of these changes and their response to exercise training.

Adverse changes in tendon–muscle physiology and physical function caused by an isolated acute rheumatoid knee effusion: A case study

Introduction Patients with rheumatoid arthritis (RA) have reduced muscle mass, probably due to the catabolic effects of systemic inflammation and disuse (1). This loss leads to reduced strength and physical function (1,2). In addition, the presence of effusion in the knee joint results in reflex inhibition of the quadriceps as demonstrated by reduced electromyogram (EMG) activity and diminished strength (3,4). The wider characteristics of the tendon–muscle complex have not been investigated in acute RA or in joint effusions of other etiologies. In exercise science, electrophysiologic methods are used to investigate tendon– muscle properties in healthy populations. These include assessments of muscle-specific force (force/cross-sectional area), architecture (fiber fascicle length and pennation angle), voluntary activation capacity, contractile properties, and tendon stiffness. Application of these techniques in aging and disuse has demonstrated adverse changes in tendon and muscle properties that result in impaired function but respond well to exercise training (5,6). We have previously applied these methods in patients with well-controlled RA and found that tendon stiffness was reduced (Matschke V et al: unpublished observations), while muscle quality (specific force, voluntary activation capacity, contractile properties) was unaffected (7,8). To our knowledge, these electrophysiologic methods have not been applied in acute RA, probably due to difficulties arising from confounding factors such as pain, fatigue, and the acute effects of inflammation in other joints.