Inclusion Criteria:  >18 years of age.  Exclusion Criteria:  BMI >40 kg/m2  History of nerve damage or sensory deficit in the lower limbs (including frostbite) Hypersensitivity to cold, including hives Active inflammation or pain of the knee History of thrombosis, embolism, or other conditions related to impaired peripheral circulation Suffering from diagnosed diabetes, multiple sclerosis, rheumatoid arthritis, spinal cord injury, cardio-vascular disease, hypertension, Raynaud disease, cryoglobulinemia, or haemoglobinuria Confirmed or suspected tissue infection, an unstable fracture, a skin condition, or a tumour in the treatment area Cognitive impairment or communication barriers  These criteria have been selected in accordance with the common contraindications for cold therapy (Selfe et al, 2009; Fang et al, 2012; Waterman et al, 2012) and those laid out in the manufacturer's guidelines of the specific device to be used (S1; Physiolab Technologies Ltd)