Lower Back Pain and Older Adults: What Are the Threats to Future Mobility?

In a given year, lower back pain affects between one-third and two-thirds of older adults. A new study sought to determine if such pain in well-functioning older adults spurs declines in mobility. Results were mixed but the issue deserves further research, the authors reported.

The study, published in the Journal of the American Geriatrics Society, examined the potential contribution of severity of lumbopelvic pain (LPP) in 878 older adults aged 60 to 89. Researchers examined LPP's effects on poorer walking efficiency, lack of endurance, slower gait speed, and decline in these parameters over 1 to 5 years.

An interviewer-administered questionnaire was used to determine reported presence and severity of back and hip pain in the preceding 12 months and reported walking ability, including ease of walking a mile.

Participants were assessed for their usual gait speed, the energetic cost of walking (oxygen consumption, mL per kg/m), and time to walk 400 meters as quickly as possible.

Overall, 31.4% had mild LPP, and 15.7% had moderate to severe LPP.

In adjusted analyses, reported walking ability (P <.001), endurance walk performance (P <5.007), and energetic cost of walking (P <5.049) were worse with increasing LPP severity.

Usual gait speed did not vary according to LPP (P <5.31). Longitudinally, over an average of 2.3 years, persons with new or sustained LPP had worse follow-up level, greater mean decline, and higher likelihood of meaningful decline in reported walking ability than persons free of LPP or whose LPP resolved. Walking performance did not differ according to LPP follow-up status.

Overall, LPP was common in these older adults and was associated with greater energetic cost of walking and poorer perceived and observed walking endurance. The longitudinal effect of LPP is unclear. However, the worsening perception of walking ability and its contribution to future mobility loss warrants further examination, the researchers reported.

In addition to being well-functioning, this study group was also highly active, with more than 40% spending at least 150 minutes per week in exercise-related activities, in contrast to about 3% of the general older adult population.

The higher activity levels may explain the high rates of LPP, but whether greater activity contributes to LPP or increases awareness of existing LPP cannot be determined. Nevertheless, this observation that LPP prevalence is high in a highly active population supports known concerns that inactivity may hide prevalent back pain and that the effect of back pain on walking endurance may be underappreciated.

The author wrote that the “potential implications of worse perceived walking ability for walking endurance and efficiency may depend on how individuals respond to diminished ease of walking, and even then, the consequences of any activity restriction for sustained mobility decline may not emerge until much later.”

Participants were drawn from the Baltimore Longitudinal Study of Aging, which began in 1958 as a continuous-enrollment cohort study of normative aging, with eligibility restricted to persons free of cognitive impairment, functional limitations, chronic diseases, and cancer within the previous 10 years. This work was supported by the Intramural Program of the National Institute on Aging.

Reference

Simonsick EM, Aronson B, Schrack JA, et al. Lumbopelvic pain and threats to walking ability in well-functioning older adults: findings from the Baltimore Longitudinal Study of Aging [published online February 7, 2018]. J Am Geriatr Soc. doi: 10.1111/jgs.15280.