Local and Systemic Cardiovascular Effects from Monochromatic Infrared Therapy in Patients with Knee Osteoarthritis: A Double-Blind, Randomized, Placebo-Controlled Study
Table 2
Changes in heart rate, blood pressure, and blood flow velocity.
Time point
Treatment group
Placebo group
Mean between group difference
Repeated-measure ANOVA
P value (F value)
Mean (SD)
Mean (SD)
(95% confidence interval)
Group
Time
Time × group
Heart rate (beats/min)
Initial score
69.6 (10.2)
72.2 (11.5)
−2.3 (−7.4, 2.8)
0.918
0.340
0.160
After 40 min of treatment
65.8 (8.0)
67.6 (11.2)
−1.8 (−6.4, 2.8)
( = 0.01)
( = 1.12)
( = 1.74)
5 min after treatment
65.1 (8.5)
64.3 (10.4)
−0.2 (−4.8, 4.5)
10 min after treatment
65.8 (9.2)
65.8 (10.7)
−0.9 (−5.9, 4.1)
15 min after treatment
64.9 (10.1)
67.8 (11.7)
−3.6 (−8.7, 1.6)
Systolic blood pressure (mmHg)
Initial score
120.3 (16.5)
121.1 (17.6)
−0.8 (−8.9, 7.3)
0.281
0.180
0.861
After 10 min of treatment
111.8 (17.0)
114.0 (20.7)
−2.2 (−11.1, 6.8)
( = 1.18)
( = 1.53)
( = 0.38)
After 20 min of treatment
109.3 (17.3)
114.6 (24.8)
−5.3 (−15.4, 4.8)
After 30 min of treatment
111.6 (17.5)
117.3 (21.0)
−5.7 (−14.8, 3.5)
After 40 min of treatment
112.8 (20.4)
116.4 (14.5)
−3.6 (−12.0, 4.8)
5 min after treatment
116.1 (16.8)
117.4 (19.6)
−1.3 (−10.0, 7.3)
15 min after treatment
114.1 (15.0)
119.9 (17.3)
−5.9 (−13.6, 1.8)
Diastolic blood pressure (mmHg)
Initial score
73.8 (12.0)
70.8 (11.3)
3.0 (−2.5, 8.5)
0.262
0.663
0.757
After 10 min of treatment
73.1 (12.0)
70.5 (12.0)
2.6 (−3.1, 8.3)
( = 1.28)
( = 0.65)
( = 0.53)
After 20 min of treatment
69.7 (12.7)
70.1 (12.7)
−0.4 (−6.5, 5.6)
After 30 min of treatment
70.6 (10.8)
72.9 (14.5)
−2.3 (−8.4, 3.7)
After 40 min of treatment
72.3 (14.1)
72.8 (11.8)
−0.5 (−6.6, 5.7)
5 min after treatment
73.7 (11.1)
74.6 (10.7)
−0.9 (−6.1, 4.3)
15 min after treatment
73.8 (12.0)
74.9 (12.1)
−1.1 (−6.8, 4.7)
Blood flow velocity (meters/sec)
Initial score
36.3 (11.0)
40.5 (10.9)
−3.7 (−8.9, 1.5)
0.666
0.323
0.769
After 40 min of treatment
39.6 (10.8)
41.1 (11.3)
−1.4 (−6.6, 3.8)
( = 0.19)
( = 1.17)
( = 0.38)
5 min after treatment
40.6 (11.6)
41.6 (11.5)
−1.0 (−6.4, 4.3)
10 min after treatment
40.8 (11.6)
40.3 (10.5)
−0.2 (−5.5, 5.2)
15 min after treatment
39.7 (10.6)
40.9 (10.5)
−1.2 (−6.2, 3.8)
Note: scores are presented as the mean (standard deviation) for each variable.
