Quantitative Evaluation of Muscle Function, Gait, and Postural Control in People Experiencing Critical Illness After Discharge From the Intensive Care Unit.

BACKGROUND

The path to recovery of muscle strength and mobility following discharge from the intensive care unit (ICU) has not been well described.

OBJECTIVE

The study objective was to quantify muscle function, gait, and postural control at 3 and 6 months after discharge in people who were recovering from critical illness and who were ventilated for 7 days or more.

DESIGN

This was a nested longitudinal study with continuous inclusion of individuals over a 2-year period and with age- and sex-matched controls.

METHODS

Twenty-four people were tested at 3 months after ICU discharge; 16 of them (67%) were reevaluated at 6 months (post-ICU group). Healthy controls (n = 12) were tested at a single time point. Muscle function of the knee extensors (KEs), plantar flexors (PFs), and dorsiflexors (DFs) was assessed on a dynamometer. Gait was measured using an electronic walkway, and postural control was measured with 2 portable force plates.

RESULTS

Muscle weakness was observed across all muscle groups at 3 months, with the greatest strength reductions in the ankle PFs (45%) and DFs (30%). Muscle power was reduced in the PFs and DFs but was not reduced in the KEs. Gait in the post-ICU group was characterized by a narrower step, longer stride, and longer double-support time than in the controls. Improvements were found in KE strength and in stride time and double-support time during gait at 6 months. Leg muscle strength and power had moderate associations with gait velocity, step width, and stride length (r = .44–.65).

LIMITATIONS: The small heterogeneous sample of people with a high level of function was a limitation of this study.

CONCLUSIONS

Muscle strength and power were impaired at 6 months after ICU discharge and were associated with gait parameters. Future studies are needed to examine the role of muscle strength and power training in post-ICU rehabilitation programs to improve mobility.