Effect of obesity onset on pendular energy transduction at spontaneous walking speed: Prader–willi versus nonsyndromal obese individuals

Abstract

Objective: To compare the mechanical external work (W ext ) and pendular energy transduction (R step ) at spontaneous walking speed (S s ) in individuals with Prader-Willi syndrome (PWS) versus subjects with nonsyndromal obesity (OB) to investigate whether the early onset of obesity allows PWS subjects to adopt energy conserving gait mechanics. Design and Methods: W ext and R step were computed using kinematic data acquired by an optoelectronic system and compared in 15 PWS (BMI ¼ 39.5 6 1.8 kg m À2; 26.7 6 1.5 year) and 15 OB (BMI ¼ 39.3 6 1.0 kg m À2; 28.7 6 1.9 year) adults matched for gender, age and BMI and walking at S s . Results: S s was significantly lower in PWS (0.98 6 0.03 m s À1) than in OB (1.20 6 0.02 m s À1; P < 0.001). There were no significant differences in W ext per kilogram between groups (PWS: 0.37 6 0.04 J kg À1 m À1; OB: 0.40 6 0.05 J kg À1 m À1; P ¼ 0.66) and in R step (PWS: 69.9 6 2.9%; OB: 67.7 6 2.4%; P ¼ 0.56). However, R step normalized to Froude number (R step /Fr) was significantly greater in PWS (6.0 6 0.6) than in OB (3.8 6 0.2; P ¼ 0.001). Moreover, R step /Fr was inversely correlated with age of obesity onset (r ¼ À0.49; P ¼ 0.006) and positively correlated with obesity duration (r ¼ 0.38; P ¼ 0.036). Conclusion: Individuals with PWS seem to alter their gait to improve pendular energy transduction as a result of precocious and chronic adaptation to loading.

External Mechanical Work and Pendular Energy Transduction of Overground and Treadmill Walking in Adolescents with Unilateral Cerebral Palsy

“…However, in a previous study (Eames et al, 1999 ) there was no actual difference between the excursion of a single anatomical point and COM during normal and pathological gait in children. Moreover, W ext was significantly correlated between the two methods in further studies (Meichtry et al, 2007 ; Yang and Pai, 2014 ) and our two groups were compared using the same methodology, which has already been used in adults (Malatesta et al, 2009 , 2013 ) and children (Peyrot et al, 2009 , 2010 ). In contrast to the reference methods usually used to obtain the COM motion (anthropometric modeling and kinematic analysis and ground reaction forces), our method is simple, cheap, consumes little time, and allows clinicians to easily assess the mechanics of overground and treadmill walking in a normal corridor and with a normal treadmill respectively.…”

The Motion of Body Center of Mass During Walking: A Review Oriented to Clinical Applications

“…Given the velocity adopted, a normal W ext,m and/or a normal 3D path of the CoM (see below) can be observed in symmetric impairments. This has been found to be the case in scoliosis (81), multiple sclerosis (82), obesity (83), non-freezing Parkinson's disease (84), and hemophilic arthropathies (85). In most pathologic conditions, steps tend to be even shorter (hence, their cadence higher) than is physiologically necessary for the lower speed that is adopted.…”

Clinical usefulness and challenges of instrumented motion analysis in patients with intellectual disabilities

“…Twelve studies had a case-control design [19][20][21][22][23][24][25][26][27][28][29][30], four were cross-sectional studies [31][32][33][34], two were cohort studies [35,36] and two were randomized controlled trials [37,38].…”

“…Twelve studies investigated syndrome-specific ID populations, of which five were Down syndrome (DS) [21][22][23][24][25]29], two were Prader -Willi syndrome (PWS) [27,35], one Cri du Chat syndrome (CDC) [19], one Fragile -X associated tremor/ataxia syndrome (FXAT+) [39], one Rett syndrome (RS) [36], one Rubinstein -Taybi syndrome (RTS) [20] and one Williams syndrome (WS) [24]. Three studies combined various etiologies such as Down syndrome with other unknown syndromes [37,38] or Down syndrome with autism spectrum disorder and pervasive developmental disorders [26].…”