Immediate muscle strengthening by an end-effector type gait robot with reduced real-time use of leg muscles: A case series and review of literature

Table 1 Demographic characteristics

Subjects	Age (yr)	Sex	Weight (kg)	Height (cm)	Evaluated side	Walking speed on a floor (km / h)	Protocol deviation
001	34	M	81.3	176.8	Right	2.3	+
002	38	F	70.0	163.1	Right	2.4
003	27	M	78.0	177.9	Right	2.1
004	34	M	85.0	172.9	Right	2.8
005	28	M	85.0	186.1	Right	2.6
006	30	F	50.3	160.5	Right	2.1
007	22	F	54.0	156.2	Right	2.5
008	24	F	70.0	169.8	Right	2.4
009	35	M	74.0	178.0	Left	2.9
010	24	M	70.0	180.1	Right	3.1
011	49	M	60.0	174.9	Left	2.8
012	45	F	63.0	174.0	Right	2.0	+

Table 2 Comparison of peak torque and motor unit recruitment

Dominant side	Peak torque (Nm / kg)		Maximal ratio of torque development(Nm / s· kg)
	mean ± SE	95%CI
Knee flexors
Before intervention	42.2 ± 15.7	10.9 - 73.5	71.2 ± 32.3
After training on the floor	51.4 ± 20.5a	10.5 – 92.3	65.3 ± 19.7
After training in the robot	61.0 ± 24.2ac	12.7 - 109.4	68.0 ± 24.0
Knee extensors
Before intervention	85.6 ± 23.5	38.7 – 132.6	68.3 ± 6.2
After training on the floor	100.0 ± 29.8a	40.5 - 159.5	70.5 ± 6.5
After training in the robot	104.4 ± 32.5ac	39.4 – 169.4	70.5 ± 8.8

^aP < 0.01 vs before intervention, Kruskal Wallis test.

^cP < 0.01 vs after training on the floor, Mann-Whitney test.

Table 3 Comparison of the real-time electromyographic activities during five-minute training

Dominant side	Intervention	Real-time mean amplitude (mV)	Real-time peak amplitude (mV)	Real-time mean value of AUC (cm2 / s)	Real-time total value of AUC (cm2 / 5 min)
Biceps femoris long head	On the floor	90.7 ± 0.3	473.3 ± 139.8	75.6 ± 11.6	13933489 ± 2142999
	In the robot	90.1 ± 0.8	89.3 ± 8.5a	16.4 ± 1.6a	3028676 ± 296582a
Vastus medialis	On the floor	90.2 ± 0.6	517.2 ± 115.4	68.5 ± 12.2	12631555 ± 2240388
	In the robot	89.8 ± 0.3	192.5 ± 23.6a	42.2 ±3.1a	7781851 ± 579361a
Gastrocnemius medial head	On the floor	90.1 ± 0.3	599.5 ± 124.4	89.2 ± 11.2	16444668 ± 2059635
	In the robot	90.6 ± 1.1	142.9 ± 23.5a	25.9 ± 4.8a	4764851 ± 885854a
Tibialis anterior	On the floor	90.8 ± 0.5	812.8 ± 174.5	115.3 ± 19.6	21254,406 ± 3610903
	In the robot	89.9 ± 0.4	92.0 ± 19.5a	13.9 ± 2.2a	2568851 ± 404428a

^aP < 0.01, Wilcoxon sign rank test, mean ± SE. AUC: Area under curve.