Lower body positive pressure: an emerging technology in the battle against knee osteoarthritis?

Figures & data

Figure 1 Subject walking on a G-Trainer treadmill under lower body positive pressure support.

Table 1 Descriptive information for the sample patient populationa

Participants	Total (mean ± standard deviation)
Number	22 (5 male/17 female)
Age (years)	52.9±6.4
Height (m)	1.67±0.1
Weight (kg)	93.7± 18.5
Body mass index (kg/m^2)	33.6±6.5
Leg alignment (Var/N/Val)	3/1/18
Physical activity levels (min/week)	711±574

Note:

a Values are representative of a homogenous sample representative of an overweight/obese early-onset knee osteoarthritis patient population.

Abbreviations: N, neutral; Val, valgus; Var, varus.

Table 2 Percentage of support required to minimize acute knee pain during lower body positive pressure (LBPP)-supported walking

Walking time (N = 22)	Percentage of LBPP support Mean ± standard deviation (range)
5 mins	I2.3±7.5 (5–30)
10 mins	12.3+7.5 (5–30)
15 mins	I2.6±7.5 (5–30)
20 mins	I2.6±7.5 (5–30)
Total	I2.4±7.4

Table 3 Acute knee pain during walkinga

Walking time (N = 22)	LBPP walking Mean ± SD	FWB walking Mean ± SD
5 mins	19.6±18.6 (11.4–27.8)	24.6±16.5 (17.3–31.9)
10 mins	21.5±20.5 (12.4–30.6)	27.9± 17.8 (20.0–35.8)
15 mins	23.2±23.0 (12.7–33.7)	31.4+21.5 (21.8–40.9)
20 mins	26.4±24.1 (15.1–37.7)	33.9±24.3 (23.1–44.6)
Total	22.6±21.5	30.0±20.l*

Notes:

a Comparison of participant knee pain (mean ± standard deviation [SD]) and confidence intervals (95% CI) as measured by the visual analog scale (mm) for 20 minutes of treadmill walking (recorded at 5-minute intervals) under lower body positive pressure (LBPP)-supported and full weight-bearing (FWB) walking conditions.

* P<0.05.

Figure 2 Change in knee pain during walking.^a

Notes: ^aMean change in pain as measured on the visual analog scale (VAS) during treadmill walking and expressed relative to the patients’ baseline pain score (which was representative of zero). Over the four intervals, pain increased significantly in the full weight-bearing (FWB) condition (*P=0.002; 95% confidence interval 5.3–20.7) but not in the lower body positive pressure (LBPP) condition (P=0.58; 95% confidence interval −16.0–9.2).

Table 4 Knee Injury and Osteoarthritis Outcome Score (KOOS) scoringa

KOOS category	Walking session 1 Mean ± SD	Walking session 2 Mean ± SD	One week postwalking Mean ± SD
Pain	48.9±16.0	51.0±15.9	54.6±16.6
Symptoms	48.2±17.5	46.2±16.6	53.6±17.6
Function in daily living	59.5±20.8	56.9±17.9	63.2±20.1
Sports/recreation	22.3±23.0	23.7±18.1	29.2±27.9
Quality of life	28.4±22.1	29.3±17.6	35.9±20.3

Note:

a KOOS data were consistent with previous reports for a knee osteoarthritis patient population, with no significant changes in KOOS scoring being noted between any of the three data collection periods.

Abbreviation: SD, standard deviation.