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.
SENSORS BUILT-IN SMARTPHONES ARE SENSITIVE TO BASE SUPPORT CHANGES IN COMMUNITY DWELLING ELDERLY / Colpo, M; Baccini, M; Mellone, S; Chiari, L; Iacopozzi, P; Bandinelli, S. - In: THE GERONTOLOGIST. - ISSN 0016-9013. - ELETTRONICO. - 55:Suppl.2(2015), pp. 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.
