Assessing Physical Activity Using Accelerometers in Youth with Duchenne Muscular Dystrophy

Abstract

Background: Physical activity, assessed by accelerometers, has been proposed as a quantitative outcome measure for patients with DMD, but research is limited Objective: To assess the total amount and patterns of physical activity in patients with DMD using accelerometers. Methods: Physical activity was assessed in patients with DMD (n = 49, 13.6 ± 4.0-year-old) and age-and sex-matched healthy controls (n = 15, 14.0 ± 2.3-year-old) using wrist-and ankle-worn accelerometers. To assess the amount of activity, accelerometer recordings were converted into acceleration estimates (counts/min). Patterns of activity were assessed as the time that participants spent in sedentary, low-intensity, and moderate-to-vigorous physical activity categories. The sedentary category was divided into three (sedentary-1,-2, and-3) and the low-intensity into two (low-intensity-1, and-2) subcategories. Results: Physical activity across intensity categories differed between study groups (p < 0.001). Patients with DMD spent on average 98.8% of their daytime in the sedentary and low-intensity categories. Compared to non-ambulatory, ambulatory patients spent more time in sedentary-3 and low-intensity-2 subcategories (p < 0.001). Amount of activity was lower in all patients than controls (p < 0.05) and in non-ambulatory than ambulatory patients and controls (p < 0.001), but similar between ambulatory patients and controls. Activity measures in patients were significantly affected by age and ambulation status (p < 0.05) but not corticosteroid use. Conclusion: Patients with DMD spent most of their daytime in sedentary and low-intensity activities. Dividing these intensities into three and two subcategories, respectively, allows better characterization of activity patterns in DMD. Ambulation status and age but not corticosteroid use affected activity measures in patients with DMD.

Objective and subjective measures of sleep in men with Muscular Dystrophy

“…Participants wore a wrist-watch triaxial accelerometer (GENEACTIV, Kimbolton, Cambs, United Kingdom) over a consecutive 7 day period [ 53 ], which has been reported as reliable and valid previously [ 54 , 55 ]. All participants wore accelerometers on the wrist to increase adherence and remove the potential discomfort of waist-worn accelerometers for non-ambulant participants [ 56 ]. Furthermore, the use of accelerometers to assess sleep has shown 83–89% agreement with polysomnography [ 57 , 58 ], and has become a more common assessment method due to participant convenience compared to polysomnography [ 59 – 62 ].…”

Technology outcome measures in neuromuscular disorders: A systematic review

“…On the other hand, one longitudinal study on CMT patients found that measuring walking activity with SAM was more sensitive than 6MWT in detecting disease progression at 12 months [24]. The content and discriminant validity of ActiGraph, a triaxial accelerometer mounted on an elastic belt around the waist, was demonstrated in different NMDs (ALS, DMD) [25][26][27][28], although criterion validity was not verified against manual step count in CMD patients, possibly because of gait impairment [29]. Finally, two studies explored the psychometric properties of the 95th percentile of stride velocity (SV95C), measured by Actimyo, in ambulant DMD patients [30,31].…”

Quantitative assessment of sitting time in ambulant adults with Muscular Dystrophy

“…Physical Behaviour monitoring was successfully completed by all participants over 7 days, with 0 non-wear time. The tri-axial accelerometers were worn on the wrist rather than hip or thigh in order to increase adherence, as demonstrated in MD and non-MD populations [19,31,32].…”

“…Recently, SB has been shown to occupy 83-89% of waking hours in a mixed group of ambulatory and nonambulatory adults with MD, compared to 59% SB time in healthy controls [18]. The inclusion of both ambulatory and non-ambulatory adults with MD may be problematic in the assessment of SB, as SB time is known to be 20% lower in non-ambulatory compared to ambulatory boys with Duchenne MD (SB time = 91% in Non-Ambulant, and 71% in Ambulant) [19]. In addition to SB determined through METs, advances in accelerometry have now allowed posture classification, time spent Sitting or Standing in waking hours, to be identified [20], which has only previously been reported (9.1 Hours) using self-report methods in ambulant adults with MD [21].…”