This is a multi-center, exploratory, estimation study in both adult and pediatric populations. There is no investigational product injection during this study The exploratory objective of this study is to evaluate the anatomical characteristics of both anterolateral thighs in healthy adult and healthy pediatric populations (2 to 17 years old) by ultrasound scan before and while applying a force similar to the ZENEO® triggering force.

In the healthy adult population, anatomical characteristics of one shoulder (deltoid) and one upper arm (biceps and triceps) will also be evaluated by ultrasound scan before and while applying a force similar to ZENEO® triggering force.

Only ultrasound procedures will be performed using an investigational ultrasound system. All subjects will be asked to undergo 1 on site visit (Study Visit) during which the eligibility assessment and the ultrasound scans will be performed.

The exploratory endpoints are as follows:

• The skin-to-muscle distance (STMD) (mm) before and while applying a force on both anterolateral thighs, one shoulder (deltoid), and one upper arm (biceps and triceps) in the adult population and both anterolateral thighs in the pediatric population
• The skin-to-bone distance (STBD) (mm) before and while applying a force on both anterolateral thighs, one shoulder (deltoid), and one upper arm (biceps and triceps) in the adult population and both anterolateral thighs in the pediatric population
• The thickness of skin layers (mm) (thickness of dermis, thickness of hypodermis [ie, subcutaneous fat]) before and while applying a force on both anterolateral thighs, one shoulder (deltoid), and one upper arm (biceps and triceps) in the adult population and both anterolateral thighs in the pediatric population
• The thickness of muscle layers (mm) before and while applying a force on both anterolateral thighs, one shoulder (deltoid), and one upper arm (biceps and triceps) in the adult population and both anterolateral thighs in the pediatric population

Inclusion Criteria:

1. Male or female, 2 to 70 years old, inclusive
2. In stable health, as determined by medical history and physical examination at screening (ie, any chronic medical diagnoses or conditions should be stable and well managed, with no significant changes expected during assessments, so that in the opinion of the investigator or designee there will not be any impact on the ability of the subject to participate in the study)
3. For the adult population, body mass index (BMI) ≥ 18.5 and ≤ 35 kg/m2 at screening BMI = weight (kg)/(height [m])2
4. Willing and able to provide written informed consent and assent (as appropriate) prior to initiation of study procedures
5. Subjects must be able to communicate effectively with the study staff and to understand study instructions (not applicable for toddlers and preschoolers)

Exclusion Criteria:

1. Any skin or muscular condition, such as eczema, scars, infections, moles, or tattoos at the site of measurements
2. Allergy to ultrasound gel
3. Any other condition or prior therapy that, in the investigator or designee's opinion, would make the subject unsuitable for the study, or unable or unwilling to comply with the study procedures
4. Is an employee or authorized representative of CROSSJECT SA or ICON plc
5. Adult under guardianship or subject incarcerated