Temporal Asymmetry Limited in Assessing Unilateral Knee Pain in Osteoarthritis

Among individuals with unilateral knee pain in osteoarthritis (OA), temporal asymmetry during walking is not related to pain severity, according to study results published in Arthritis Care & Research (Hoboken).

In an exploratory analysis of the prospective Multicenter Osteoarthritis (MOST) cohort study, researchers sought to explore the relationship of unilateral knee OA pain severity with temporal asymmetry during walking, as well as to establish relationships between temporal asymmetry during walking and 2-year changes in ipsilateral and contralateral knee pain among individuals with mild to moderate unilateral knee pain.

Individuals with unilateral knee pain who were enrolled in the MOST study and aged between 50 and 79 years were included in the current analysis.

Gait was evaluated during self-selected and fast walking at baseline. Knee pain was evaluated at baseline and at 2 years. Limb symmetry indices (LSIs) — nonpainful limb/painful limb x 100 — were calculated with regard to stance, single-limb support, and double-limb support times. These relationships were then studied with regard to unilateral knee pain severity, incident contralateral knee pain, and persistent ipsilateral knee pain.

Of a total of 3026 participants in the MOST study, 127 were eligible for the cross-sectional analysis and 105 for further longitudinal analysis.

Results of the study demonstrated that unilateral knee pain severity was not related to temporal asymmetry during self-selected or fast walking. At 2 years, 18 (17.1%) participants experienced incident contralateral knee pain and 54 (51.4%) reported persistent ipsilateral knee pain.

Regarding self-selected walking, greater LSIs (ie, longer time on the nonpainful limb) for stance and single-limb support were associated with decreased odds of incident contralateral knee pain. After adjusting for sex, age, body mass index, race, symptoms of depression, gait speed, and Kellgren Lawrence grades, a 2.5% increase in stance and single-limb support LSIs during self-selected walking were associated with a 51% (odds ratio [OR], 0.49; 95% CI, 0.27-0.91) and a 37% (OR, 0.63; 95% CI, 0.41-0.96) decreased odds of incident knee pain, respectively.

Further, temporal asymmetry measures were not associated with persistent ipsilateral knee pain other than for single-limb support LSI during rapid walking, after adjusting for the average number of steps per day. This relationship demonstrated that a 2.5% increase in single-limb support LSI was associated with a 59% (OR, 1.59; 95% CI, 1.05-2.41) increased risk for persistent ipsilateral knee pain. 

In addition, measures of temporal asymmetry were not linked to persistent ipsilateral knee pain other than for single-limb support during rapid walking.

A key limitation of the study was that the sample only included individuals with mild or moderate pain with walking. An additional limitation was that temporal measures of gait may not have been good surrogates for knee joint loading and may not have captured the concept that the researchers were attempting to evaluate.

Study authors concluded that “These findings [suggested] that measures of temporal asymmetry [held] little value in explaining the progression from unilateral to bilateral knee OA.”

This article originally appeared on Rheumatology Advisor