This trial studies how well an ultrasound procedure (non-invasive MuscleSound technology) can be used to learn about levels of glycogen (a type of sugar) in cancer patients during inpatient rehabilitation. The ultrasound information will be processed to represent the energy storage in the muscle. The energy storage in the muscle may help future research to look for dietary plans that can help to increase energy storage, patient exercise tolerance, and functional improvement.

PRIMARY OBJECTIVES:

I. Determine feasibility of using non-invasive MuscleSound technology to determine glycogen stores in cancer patients.

EXPLORATORY OBJECTIVES:

I. Determine the baseline glycogen storage in two different groups of cancer patients, who are undergoing inpatient rehabilitation: (1) those with cachexia; (2) those without cachexia.

II. Determine the rate of depletion of muscle-glycogen stores by calculating the "Fuel Rating" score (FRS) at baseline, after 10-min of exercise and then again after 20-min of exercise.

III. Determine if there is any correlation between muscle-glycogen (at baseline and its depletion rate over time) and other factors including cancer type, cancer stage, patient age, patient sex, current body mass index (BMI), presence or absence of cachexia, functional measures and patient reported outcomes.

OUTLINE:

Patients undergo ultrasound via MuscleSound technology over 3 minutes at baseline and immediately after each of 2 physical therapy sessions comprising cycling or walking over 10 minutes.

Inclusion Criteria:

• Participants are willing and able to give written informed consent and to comply with study procedures.

• Patients with a biopsy-confirmed solid malignant neoplasm with at least one neurologically-intact lower extremity, who fit into one of the following groups:

  • Group 1: Patients with cachexia, defined by loss of > 5% of body weight over the preceding 6-months (in absence of simple starvation defined as intentional weight loss) or weight loss > 2% with BMI < 20.
  • Group 2: Patients without cachexia, as defined above.

• Patients who have a record of weight or BMI over preceding 6-months.

• Patients must be receiving rehabilitation that includes exercise under the direction of a physical therapist.

Exclusion Criteria:

• Non-English speaking patients.
• Patient with neurological compromise of both lower extremities causing muscle atrophy.
• Underlying unstable medical condition (i.e: cardiac, pulmonary, or hematological) or musculoskeletal injury, which in the opinion of the investigator, limits participation in exercise of the measured lower extremity.
• Patients who are unable to understand or follow through with study instructions.