Robotic assessment of the influence of age on upper-limb sensorimotor function

Figures & data

Figure 1 RoboTherapist 2D robotic device used in this study to monitor the reaching task.

Figure 2 A participant grasping the robot end effector in the setup position.

Figure 3 Targets and feedback presented to the participant using the REVIRE software.

Table 1 Participants: summary demographic data

	Group 1 (20–40 years) Mean: 28.3	Group 2 (41–60 years) Mean: 50.1	Group 3 (61–80 years) Mean: 69.2	Total
Men	9	7	7	23
Women	8	10	10	28
Total	17	17	17	51

Figure 4 Movement parameters calculated from position data recorded by the RoboTherapist 2D robotic device as described in Coderre et al.⁵

Figure 5 Movement parameters calculated from tangential velocity data recorded by the RoboTherapist 2D robotic device as described in Coderre et al.⁵

Table 2 Descriptive statistics, median, skewness, and kurtosis for the three age groups

	Age group	Median		Skewness		Kurtosis
		DA	NDA	DA	NDA	DA	NDA
Postural speed (mm/second)	1	0.690	0.660	−0.208	1.003	−0.717	1.585
	2	0.730	0.740	1.777	0.664	4.743	−0.238
	3	0.870	0.690	1.815	0.712	3.338	0.716
Reaction time (seconds)	1	0.400	0.400	0.493	−0.023	0.962	0.425
	2	0.430	0.430	0.065	−0.253	−1.117	−0.670
	3	0.440	0.440	−1.640	0.929	5.394	0.388
Initial movement direction error (°)	1	9.550	9.760	0.126	−0.558	−1.523	−0.451
	2	10.94	9.280	0.894	0.960	0.137	1.262
	3	18.77	13.29	0.061	1.179	−0.917	2.403
Initial movement ratio	1	0.620	0.630	0.208	−0.275	−0.472	0.667
	2	0.600	0.590	−2.087	−0.283	5.550	−0.729
	3	0.290	0.490	0.487	−0.256	−1.094	−1.059
Maximum speed (mm/second)	1	146.49	155.24	1.599	1.257	2.887	2.928
	2	135.88	137.46	−1.238	0.013	1.248	0.237
	3	92.04	109.39	1.134	1.291	2.535	1.878
Path length (mm)	1	95.91	94.87	0.007	1.862	−0.863	3.143
	2	97.95	94.85	3.125	0.753	11.467	1.294
	3	98.63	97.61	−3.382	−0.161	13.317	−0.967
Movement time (seconds)	1	0.860	0.810	−0.160	0.208	−0.096	−0.457
	2	0.990	0.890	1.681	1.028	2.740	0.308
	3	1.700	1.340	-0.106	0.558	−0.437	−0.101
Force (N)	1	1.550	1.550	0.134	0.139	−1.807	−1.776
	2	1.380	1.390	−0.236	0.136	−0.277	0.863
	3	1.340	1.380	−2.178	−0.065	6.697	−0.014

Abbreviations: DA, dominant arm; NDA, non-dominant arm.

Figure 6 Hand trajectories for a 67-year old, right handed, male (#38).

Notes: Hand trajectories are plotted for movements made to each of the eight targets and speed profiles are plotted for one movement direction. The dominant arm is on the left (A and C) and the non-dominant arm is on the right (B and D). Each line in the hand trajectory (A and B) and speed profile (C and D) plots represents a single trial. The blue vertical line in the speed profiles represents the time when the peripheral target was illuminated.

Figure 7 Hand trajectories for a 23-year-old, right handed, male (#5).

Notes: Hand trajectories are plotted for movements made to each of the eight targets and speed profiles are plotted for one movement direction. The dominant arm is on the left (A and C) and the non-dominant arm is on the right (B and D). Each line in the hand trajectory (A and B) and speed profile (C and D) plots represents a single trial. The blue vertical line in the speed profiles represents the time when the peripheral target was illuminated.

Table 3 Kruskal–Wallis test, dominant arm

	Postural speed	Reaction time	Initial movement direction error	Initial movement ratio	Maximum speed	Path length	Movement time	Force
X^2	2.915	8.264	19.223	19.164	17.370	7.975	23.176	7.341
df	2	2	2	2	2	2	2	2
P-value	0.233	0.016	0.000	0.000	0.000	0.019	0.000	0.025

Notes: X² is from Kruskal–Wallis H. df is equal to the number of groups minus one. P-value is the significance level (P < 0.05 significant differences among groups).

Abbreviation: df, degrees of freedom.

Table 4 Kruskal–Wallis test, non-dominant arm

	Postural Speed	Reaction time	Initial movement direction error	Initial movement ratio	Maximum speed	Path length	Movement time	Force
X^2	0.997	12.742	5.641	10.807	11.543	6.852	15.002	9.359
df	2	2	2	2	2	2	2	2
P-value	0.607	0.002	0.060	0.005	0.003	0.033	0.001	0.009

Notes: X² is from Kruskal–Wallis H. df is equal to the number of groups minus one. P-value is the significance level (P < 0.05 significant differences among groups).

Abbreviation: df, degrees of freedom.

Table 5 Pairwise comparisons of the different parameters of the dominant arm using the Mann–Whitney U test

	Group 1 vs Group 2 (20–40 vs 41–60)	Group 1 vs Group 3 (20–40 vs 61–80)	Group 2 vs Group 3 (41–60 vs 61–80)
Postural speed	0.586	0.099	0.259
Reaction time	0.057	0.011*	0.106
Initial movement direction error	0.245	0.000*	0.001*
Initial movement ratio	0.218	0.000*	0.000*
Maximum speed	0.274	0.000*	0.001*
Path length	0.085	0.006*	0.218
Movement time	0.018*	0.000*	0.000*
Force	0.031*	0.014*	0.496

Notes: Values are P-values.

* P < 0.05.

Abbreviation: vs, versus.

Figure 8 Significant movement parameters plotted for the three groups.

Notes: Group 1 (age 20–40 years), Group 2 (age 41–60 years), and Group 3 (age 61–80 years).Abbreviations: Min, minimum value; Max, maximum value.

CoderreAMZeidAADukelowSPAssessment of upper-limb sensorimotor function of subacute stroke patients using visually guided reachingNeurorehabil Neural Repair201024652854120233965

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