Bed Rest And Skeletal Muscle

Original Editor - Lucinda hampton

Top Contributors - Lucinda hampton  

Introduction

Muscle atrophy (sarcopenia) and muscle strength losses very quickly occur with prolonged bed rest. Hospitalization of ≤5 days, referring to disuse/immobilization/ or prolonged time in the supine position bed, causes significant decreases in muscle mass and size. This in turn leads to functional decline.

• There is a logarithmic disuse-induced loss of strength and muscle atrophy.
• In the first 2 wks of bed rest, muscle strength decline is much faster than muscle atrophy.

Bed Rest: Metabolic Muscle Changes

The main matabolic musclular changes are insulin sensitivity and metabolic flexibility decrease in response to bed rest.

• Muscle glycogen build-up in bed rest decreases insulin sensitivity and storage of glycogen
• Lipid overload in muscles leads to lipotoxicity causing inflammation to develop during bed rest
• Muscle metabolism from changes from fatty acid to glucose oxidation
• With long term bed rest internal mitochondrial alterations occur

Prevention

Recent research shows that exercise interventions significantly attenuate loss of muscle mass.

• The exercise interventions included resistive exercise (RE), resistive vibration exercise (RVE), flywheel resistive exercise, treadmill exercise with lower body negative pressure (LBNP) and a zero-gravity locomotion simulator (ZLS).
• With exercise intervention, high rates of bone loss were still observed.

Physiotherapy

See Exercise in Critical Care, Implementing an Early Mobility Programme for Critically Ill Patients,