010 Resistance Training Avoidance- a Benefit or Barrier to Recovery following Cardiac Surgery Via Median Sternotomy?

Abstract

Sternal precautions typically restrict upper limb movement for 1-6 weeks and resistance training for 6-12 weeks post-sternotomy. This is based on the belief that mechanical forces generated by upper limb movements act in direct opposition to the wire suture holding strength, seen in early cadaver studies. However, the safety, feasibility and reliability of resistance training on sternal micromotion is unknown. This is a nested study within a pilot randomised controlled trial comparing standard care to a 12-week resistance training program. Sixteen adults following first-time cardiac surgery via median sternotomy, who were randomised to the resistance training group participated. Sternal micromotion was assessed using sternal ultrasound of the mid- and lower- sternum during a cough and six dynamic bilateral upper limb resistance exercises at 2-, 8- and 14- weeks postoperatively, performed on CAM-machines at a base resistance of 20lbs (9kg). Participant-reported pain was recorded using a Visual Analogue Scale. Intra-class correlation coefficients (ICC) were used to calculate inter-rater reliability of sternal ultrasound image analysis. The biceps curl (M=1.5mm; IQR=1.9mm) and shoulder pulldown (M=0.5mm; IQR=1.1mm) resulted in the greatest median micromotion in the lateral and anterior-posterior directions, respectively. No increase in pain from rest was reported by any participant. Inter-rater reliability for lateral (ICC=0.73; 95% CI=0.58-0.83) and anterior-posterior (ICC=0.83; 95% CI=0.73-0.89) sternal edge micromotion was moderate-to-good. Physical and functional postoperative recovery is impacted by movement restrictions recommended within current sternal precautions. This study determined that bilateral upper limb exercises performed on CAM-resistance machines is safe in regard to sternal micromotion (<2mm) and pain as early as two weeks post-sternotomy.