Purpose and methods: The Romberg Test (RT) coupled with a force platform assesses disequilibrium and functional levels in older patients. Commercial smartphones (SPs) embed three-axial inertial sensors which are a portable and reliable alternative to a force plate for measurements of postural sway. The present study investigates the sensitivity of SPs embedded sensors for detecting different feet-position (FP) in a not-disabled community dwelling elderly persons performing RT. Samsung Galaxy SII/III were worn on the lower back (L5) by means of a waist belt. 60 subjects (25F; 80.1±6.4ys, MMSE 27.6±1.8, BMI 27.7±3.6) were recruited for performing a 30 sec eyes closed RT in two conditions: feet together (FT) and feet under the SIAS (FSIAS). Sensor-based features included: 95% confidence ellipse area (95%EA) of the CoM displacement, RMS, sway path, and mean velocity in ML-AP direction. Differences related with FP were investigated by means of paired t-test. Results: Sway path was significantly different between FT and FSIAS in ML (FT 14.5±6.2mm, FSIAS: 6.1±3.8mm, p=<0.001) but not in AP (FT 28.8±12.3mm, FSIAS 24.5±17.1mm, p=0.062). Similarly for RMS in ML (FT 7.0±3.1mm, FSIAS 3.5±2.3mm, p<0.001) and AP (FT 11.1±5.0mm, FSIAS 9.6±6.9mm, p=0.131). 95%EA was significantly different (p<0.001) between FT (1466.1±1234.5mm2) and FSIAS (582.2±1048.2mm2). Mean sway velocities were also significantly different in ML (FT 5.2±2.3mm/s, FSIAS 1.9±0.90mm/s, p<0.001) and AP (FT 6.5±2.7mm, FSIAS 4.8±1.7mm, p<0.001). Conclusion: SP embedded sensors are sensitive to FP and offer a relatively cheap and ubiquitous alternative for quantifying postural control in the clinic but also in more ecological settings.
Colpo, M., Baccini, M., Mellone, S., Chiari, L., Iacopozzi, P., Bandinelli, S. (2015). SENSORS BUILT-IN SMARTPHONES ARE SENSITIVE TO BASE SUPPORT CHANGES IN COMMUNITY DWELLING ELDERLY. THE GERONTOLOGIST, 55(Suppl.2), 391-391 [10.1093/geront/gnv179.08].
SENSORS BUILT-IN SMARTPHONES ARE SENSITIVE TO BASE SUPPORT CHANGES IN COMMUNITY DWELLING ELDERLY
MELLONE, SABATO;CHIARI, LORENZO;
2015
Abstract
Purpose and methods: The Romberg Test (RT) coupled with a force platform assesses disequilibrium and functional levels in older patients. Commercial smartphones (SPs) embed three-axial inertial sensors which are a portable and reliable alternative to a force plate for measurements of postural sway. The present study investigates the sensitivity of SPs embedded sensors for detecting different feet-position (FP) in a not-disabled community dwelling elderly persons performing RT. Samsung Galaxy SII/III were worn on the lower back (L5) by means of a waist belt. 60 subjects (25F; 80.1±6.4ys, MMSE 27.6±1.8, BMI 27.7±3.6) were recruited for performing a 30 sec eyes closed RT in two conditions: feet together (FT) and feet under the SIAS (FSIAS). Sensor-based features included: 95% confidence ellipse area (95%EA) of the CoM displacement, RMS, sway path, and mean velocity in ML-AP direction. Differences related with FP were investigated by means of paired t-test. Results: Sway path was significantly different between FT and FSIAS in ML (FT 14.5±6.2mm, FSIAS: 6.1±3.8mm, p=<0.001) but not in AP (FT 28.8±12.3mm, FSIAS 24.5±17.1mm, p=0.062). Similarly for RMS in ML (FT 7.0±3.1mm, FSIAS 3.5±2.3mm, p<0.001) and AP (FT 11.1±5.0mm, FSIAS 9.6±6.9mm, p=0.131). 95%EA was significantly different (p<0.001) between FT (1466.1±1234.5mm2) and FSIAS (582.2±1048.2mm2). Mean sway velocities were also significantly different in ML (FT 5.2±2.3mm/s, FSIAS 1.9±0.90mm/s, p<0.001) and AP (FT 6.5±2.7mm, FSIAS 4.8±1.7mm, p<0.001). Conclusion: SP embedded sensors are sensitive to FP and offer a relatively cheap and ubiquitous alternative for quantifying postural control in the clinic but also in more ecological settings.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
