Muscle anatomy and dynamic muscle function in osteogenesis imperfecta type I

Area of Science:

• Pediatric Orthopedics
• Musculoskeletal Disorders
• Biomechanics

Background:

• Previous studies indicated a muscle force deficit in children and adolescents with osteogenesis imperfecta (OI) type I.
• However, prior assessments relied on static isometric tests, not dynamic conditions.

Purpose of the Study:

• To evaluate lower extremity dynamic muscle function in individuals with OI type I.
• To assess muscle anatomy in children and adolescents with OI type I.

Main Methods:

• A study involving 54 individuals with OI type I (6-21 years) and 54 age/sex-matched controls.
• Muscle cross-sectional area and density measured via peripheral quantitative computed tomography.
• Lower extremity dynamic muscle function assessed using jumping mechanography (hopping, jumping, chair-rise, heel-rise tests).

Main Results:

• Patients with OI type I had smaller calf muscle size (P = .04) but normal muscle density (P = .21) compared to controls.
• Significantly lower average peak force and specific force were observed in OI type I patients (all P < .008).
• Average peak power was lower in OI type I patients, though not statistically significant (all P > .054).

Conclusions:

• Children and adolescents with OI type I demonstrate a significant lower limb force deficit in dynamic assessments.
• Despite group deficits, the study highlights that OI type I can be compatible with normal muscle performance in some individuals.