For total EE , correlation coefficients were statistically significantly lower in uniaxial compared to multisensor devices .
For active EE , correlations were slightly but not significantly lower in uniaxial compared to triaxial and multisensor devices .
The high level of heterogeneity in the validation studies is only partly explained by the type of activity monitor and the activity monitor outcome .
Triaxial and multisensor devices tend to be more valid monitors .
The assessment of physical activity in healthy population s and in those with chronic diseases is challenging .
The aim of this systematic review was to identify whether available activity monitors ( AM ) have been appropriately vali date d for use in assessing physical activity in these groups .
A Clinical Evaluation of a Remote Mobility Monitoring System based on SMS Messaging
The objective of this work was to evaluate the accuracy and viability of a  mobility telemonitoring system  , based on the short message service ( SMS ) , to monitor the functional mobility of elderly subjects in an unsupervised environment A clinical trial was conducted consisting of 6 elderly subjects ; 3 male , 3 female ( mean : 81.7 , SD : 5.09 ) .  Mobility was monitored using an accelerometer based portable unit worn by each monitored subject for eleven hours . Every 15 minutes the mobility of the subject was summarized and transmitted as an SMS message from the portable unit to a remote server for long term analysis . The activPALtrade Trio Professional physical activity logger  was simultaneously used for comparison with the portable unit . On conclusion of the trial each subject completed a question naire detailing their satisfaction with the portable unit and any recommendations for improvements . Overall a percentage difference of 2.31 % was found between the activPALtrade Trio and the portable unit for the detection of sitting . For the combined postures of st and ing and walking the percentage difference was calculated as 2.9 % . A bivariate correlation and regression analysis was performed on the entire data set of one subject . Strong positive correlation 's were found for the detection of sitting ( r = 0.996 ) and for the combined postures of st and ing and walking ( r = 0.994 ) . Subjects suggested that a lighter , smaller and wireless unit would be more effective
For total EE , correlation coefficients were statistically significantly lower in uniaxial compared to multisensor devices .
For active EE , correlations were slightly but not significantly lower in uniaxial compared to triaxial and multisensor devices .
The high level of heterogeneity in the validation studies is only partly explained by the type of activity monitor and the activity monitor outcome .
Triaxial and multisensor devices tend to be more valid monitors .
The assessment of physical activity in healthy population s and in those with chronic diseases is challenging .
The aim of this systematic review was to identify whether available activity monitors ( AM ) have been appropriately vali date d for use in assessing physical activity in these groups .