Tyrannosaurus Flex: Finding the "Fair-ly Normal" Grip

This is a cross-sectional study designed to collect normative grip strength data from a large sample of the general population in Minnesota. Participants will be primarily recruited from attendees of the Minnesota State Fair, a community event that draws a broad cross-section of individuals across age, sex, height and weight, providing an opportunity to collect normative data that is representative of the general population. The goal of this study is to establish reference values to inform clinical benchmarks for therapeutic use of the Dinomometer.

A designated research booth will be set up at the Minnesota State Fair with signage inviting interested fairgoers to participate in the study. A trained research team member will provide interested participants with a brief explanation of the study. Written informed consent will then be obtained from a parent or guardian on behalf of minor participants, with assent obtained from children as appropriate.

Following consent, the participant will be directed to a trained research team member who will collect demographic information including sex, age, race, ethnicity, county of residence, height, weight, and hand circumference and will log this information into a pre-prepared case report form administered via iPad. No personal identifiers such as names will be collected.

The participant will then be seated comfortably in a chair with the arm adducted and the elbow gently positioned at a 90-degree angle if possible. The research team member will record whether this position was achieved and maintained. Grip strength will be measured using the Dinomometer, a non-invasive handheld grip strength measurement device. Grip strength will be measured on each hand, with short rest breaks and alternation between hands to mitigate the effects of fatigue. Hand size will be measured by taking a circumferential measurement in centimeters of each hand using a standard plasticized dressmaker's tape laid across the distal palmar crease.

The following data will be collected from each participant: age, sex, height, weight, race, ethnicity, county of residence, hand size, hand dominance, grip strength measurements, and whether the standard testing position was achieved and maintained. All data will be recorded in the case report form on an iPad. The Dinomometer is the only device required for participation in this study. It is a non-invasive measurement tool and no drugs or additional investigational agents are required for participation.

The study should take approximately 10-15 minutes to complete for each participant including enrollment and completion of study procedures. Follow-up is not required.

Inclusion criteria

• Children between the ages of 2-12 year old who demonstrate participation interest and provide informed consent and assent (when appropriate).

Exclusion criteria

• Presence of a known musculoskeletal, neurological, or neuromuscular condition affecting upper limb strength or function (including, but not limited to, cerebral palsy, brachial plexus injury, muscular dystrophy, etc.)
• Diagnosis of a systemic condition affecting the musculoskeletal or nervous system
• Previous hand, wrist, or upper limb surgery
• History of hand, wrist, or upper limb trauma
• Current pain in either hand or upper limb
• Persons unable to follow standardized commands when presented to them in English