Efficacy of a trunk orthosis with joints providing resistive force on low-back load in elderly persons during static standing

Figures & data

Figure 1 Trunk ORF.

Notes: (A) Wearing ORF without resistive force on the chest, (B) wearing ORF with resistive force on the chest, (C) detail of link mechanism.

Abbreviation: ORF, orthosis with joints providing resistive force.

Figure 2 Biomechanical effect of ORF while static standing.

Abbreviation: ORF, orthosis with joints providing resistive force.

Figure 3 Experimental conditions.

Notes: (A) Without an orthosis, (B) with the LSO, (C) with the ORF.
Abbreviations: ORF, orthosis with joints providing resistive force; LSO, lumbosacral orthosis.

Figure 4 Positions of reflective markers and electrodes for electromyogram recording.

Notes: (A) Anterior surface, (B) posterior surface, (C) lateral surface.

Table 1 Mean and standard deviation for kinematic parameters in three standing conditions (N=15) and results of statistical analysis

	Without ORF	ORF mean (SD)	LSO	P-value	Without ORF, ORF	Without ORF, LSO	ORF, LSO
Pelvis forward tilt angle (°)	6.13 (5.07)	8.13 (6.55)	4.46 (5.77)	0.010	0.281	0.165	0.050
Thorax extension angle (°)	4.78 (3.66)	6.56 (4.12)	5.37 (3.52)	<0.001	0.004	0.172	0.021
Thorax angle on pelvis	−2.40 (7.02)	1.38 (7.62)	−3.49 (7.06)	0.001	0.022	0.619	0.013
coordinate system:
extension + (°)

Note: Data in bold are statistically significant, statistical significance was set at P<0.05.

Abbreviations: LSO, lumbosacral orthosis; ORF, orthosis with joints providing resistive force; SD, standard deviation.

Table 2 Mean and standard deviation for muscular activities in three standing conditions (N=15) and results of statistical analysis

Muscle activity	Without ORF	ORF mean (SD)	LSO	P-value	Without ORF, ORF	Without ORF, LSO	ORF, LSO
Percent IEMG
Right ES	57.75 (43.97)	45.48 (32.77)	53.58 (38.77)	0.003	0.024	0.433	0.055
Left ES	81.27 (51.07)	60.81 (51.15)	78.87 (50.29)	<0.001	0.001	1.000	0.004
Right GM	59.17 (53.07)	53.30 (60.42)	67.14 (79.43)	0.132
Left IO	152.23 (95.66)	132.09 (91.53)	127.77 (82.55)	0.010	0.117	0.037	1.000
Percent MVC
Right ES	5.86 (4.53)	4.60 (3.33)	5.43 (3.96)	0.003	0.027	0.435	0.053
Left ES	8.17 (5.09)	6.10 (5.10)	7.92 (5.01)	<0.001	0.001	1.000	0.004
Right GM	5.92 (5.30)	5.33 (6.40)	6.72 (7.94)	0.132
Left IO	15.27 (9.52)	13.25 (9.12)	12.83 (8.22)	0.009	0.114	0.037	1.000

Notes: %IEMG, integral of the EMG over 10 seconds relative to maximum. %MVC, average EMG over 10 seconds relative to maximum. Data in bold are statistically significant, statistical significance was set at P<0.05.

Abbreviations: ES, erector spinae; GM, gluteus media; IEMG, integral electromyography; IO, internal oblique; MVC, maximum voluntary contraction; LSO, lumbosacral orthosis; ORF, orthosis with joints providing resistive force; SD, standard deviation.

Table 3 Mean and standard deviation for COP trajectory in three standing conditions (N=15) and results of statistical analysis

	Without ORF	ORF mean (SD)	LSO	P-value
Trajectory of COP (m)	0.1285 (0.0610)	0.1314 (0.0454)	0.1304 (0.0481)	0.924

Abbreviations: COP, center of pressure; LSO, lumbosacral orthosis; ORF, orthosis with joints providing resistive force; SD, standard deviation.