Medial knee joint loading during stair ambulation and walking while carrying loads

Abstract

Carrying loads while walking or using stairs is a common activity of daily living. Knee osteoarthritis is associated with increased external knee adduction moment (KAM) during walking, so understanding how the additional challenges of stairs and carrying loads impact these moments is of value. Sixteen healthy individuals performed three types of MOTION (walking, stair ascent, stair descent) under three LOAD conditions (no load, carrying a 13.6 kg front load, carrying 13.6 kg load in a backpack). Three-dimensional gait analysis was used to measure KAM. Results of ANOVA showed a significant main effect of both MOTION and LOAD on peak KAM (p<0.001), but no significant MOTION x LOAD interaction (p=0.250).Peak KAM during stair ascent was about two-times those seen in stair descent (p<0.001) and was significantly higher than those seen in walking (p<0.001). Conditions with LOAD generated significantly greater KAM as compared to the no-LOAD conditions (p<0.001).These findings suggest that carrying a load of moderate magnitude while climbing stairs significantly increases the peak KAM -a risk factor associated with knee osteoarthritis.

Carrying asymmetric loads during stair negotiation

“…Furthermore, stair ascent resulted in higher external knee varus moments than walking or stair descent across loading conditions. These findings indicate that stair negotiation involves higher knee extension moments than walking [6,7] and that load carriage during stair ascent may also result in higher external knee varus moments [6][7][8].…”

“…The weight carried in the bags was normalized according to each subject's body weight. These normalized loads were based on previous studies that indicated significant kinematic and/or kinetic changes when carrying loads ranging from 10% to 20% BW [2,5,8,13]. Participants were instructed to ascend and descend a three-step staircase (step height 18.5 cm, tread depth 29.5 cm) at a preferred pace for each condition.…”

“…Previous studies have reported that unloaded stair ascent and descent required higher ankle dorsiflexion angles [6], knee flexion angles [6,7], and knee extension moments [6,7] as compared to level walking. Hall et al (2013) found that carrying symmetric loads of 13.6 kg (approximately 20% body weight) in a container in front of the body or in a backpack resulted in higher external knee varus moments than when carrying no load [8]. Furthermore, stair ascent resulted in higher external knee varus moments than walking or stair descent across loading conditions.…”

Carrying asymmetric loads during stair negotiation: Loaded limb stance vs. unloaded limb stance

“…For example, Hong and Li (2005) found that vertical ground reaction forces were higher for a 15% body weight (BW) load during stair descent and a 10% BW load during stair ascent when carrying asymmetric loads in a one-strap athletic bag [16]. Hall et al (2013) reported higher external knee varus moments when carrying symmetric loads of approximately 20% BW during stair ascent as compared to walking and stair descent [17]. These findings support the ideas that stair negotiation is more demanding on the knees than walking, load carriage increases overall loading on the body, and asymmetric load carriage may further increase frontal plane knee joint moments.…”

Peer Review #1 of "Is high-intensity interval cycling feasible and more beneficial than continuous cycling for knee osteoarthritic patients? Results of a randomised control feasibility trial (v0.2)"

“…Manuscript to be reviewed individuals with knee OA in the community. Such popularity may reflect the benefits and tolerability of these forms of exercise, with aquatic exercise and cycling imposing lower knee joint loads compared to walking, stair climbing and common resistance training exercises such as the leg extension and squat (Hall et al 2013;Heino Brechter & Powers 2002;Kutzner et al 2010;Kutzner et al 2012;Powers et al 2014).…”