Postoperative Electrical Muscle Stimulation Two

Undesirable loss of skeletal muscle mass (atrophy) is a common feature of many diseases as well as ageing, bed rest and physical inactivity. Losing muscle can lead to a reduction in one's ability to perform physical activities, and reduce independence and overall health. Muscle mass loss occurs very quickly (i.e., within a few days) after surgery. The investigators previous work has shown that neuromuscular electrical stimulation (NMES) of the thigh muscles on one side of the body can help maintain muscle mass and strength on the stimulated side after surgery. Since then, additional work has been carried out to find the most effective form of stimulation to build muscle. The current study aims to use this refined stimulation protocol in a clinical trial on the wards after major abdominal surgery. The intervention will involve delivering stimulation to both thighs in the few days after surgery, so that the investigators can assess whether this stimulation can preserve muscle mass and strength, and also, patients' ability to perform physical activities after surgery. In addition, the study will aim to find out whether any benefit provided by electrical stimulation can be increased further by taking a protein supplement at the same time.

Inclusion Criteria: * Adult patients (age 18 or over at the time of diagnosis made at MDT (multi-disciplinary team meeting) * MDT outcome of colorectal or gastric cancer or non-invasive neoplasia (tissue-proven, or radiologically diagnosed and clinically suspected) with the intention to treat with curative abdominal surgery * Agreed management plan for open or minimally invasive (laparoscopic or robot assisted) segmental abdominal (colonic or gastric) resection at the Royal Derby Hospital * Sufficient mobility and fitness to complete normal ERAS (enhanced recovery after surgery) protocols following surgery * Basic conversational spoken English language * Ability to give informed consent Exclusion Criteria: * Upper GI (gastrointestinal) cancer requiring thoracotomy/thoracoscopy * Pre-existing neuromuscular disease (including Parkinsons disease) * Pacemaker, implantable cardiac defibrillator or other implanted nerve stimulator device * Metal prostheses or other metal-work in either upper legs (hip/knee/femur) * Dementia or other cognitive problem or language barrier causing an inability to follow instructions and operate NMES machine * Inability to give informed consent * Disability preventing completion of ERAS after surgery (requiring Zimmer frame/wheeled frame/wheelchair to mobilise or bed-bound) * Peripheral vascular disease * Epilepsy * Pre-existing diagnosis of chronic kidney disease or estimated glomerular filtration rate \