Stabilization Exercises for Young Adults With Habitual Knuckle Cracking

Effects of Stabilization Exercises on Functional Performance, Proprioception, and Joint Laxity in Young Adults With Habitual Knuckle Cracking: A Randomized Controlled Trial

Habitual knuckle cracking is a widespread behavior caused by intra-articular pressure changes and gas release in synovial joints; however, its long-term effects on hand sensorimotor function, joint laxity, and overall biomechanics remain debated, with no structured clinical exercise interventions currently established. This prospective, randomized controlled trial aims to evaluate the effectiveness of a 4-week targeted stabilization exercise program focusing on the radiocarpal, metacarpophalangeal (MCP), and proximal interphalangeal (PIP) joints in young adults aged 18 to 30 years with habitual knuckle cracking. Participants are randomly allocated to either an intervention group receiving twice-weekly stabilization training (8 total sessions) or an un-exercised control group. The study hypothesizes that structured joint stabilization exercises will significantly improve wrist and finger joint position sense (proprioception), enhance upper extremity functional performance, and reduce joint laxity compared to the control group.

Inclusion Criteria:

• Age between 18 and 30 years,
• Voluntary agreement to participate and signing the Informed Consent Form following detailed study briefing,
• Willingness to attend all assessment and intervention sessions.

Exclusion Criteria:

• Having an occupation that requires intensive or repetitive use of the upper extremities and fingers,
• History of prior musculoskeletal injury involving the upper extremity or hand,
• Presence of physical or sensory impairments (such as visual or auditory deficits) that could interfere with study procedures,
• History of congenital or acquired orthopedic, neurological, or rheumatological conditions affecting hand or wrist range of motion and function,
• History of hand or wrist trauma requiring medical, conservative, or surgical management within the past 6 months,
• Presence of active skin lesions in the intervention region, including burns, cellulitis, vesicles, bullae, psoriasis, open or closed wounds, scar tissue, active infection, or malignancy,
• Body Mass Index (BMI) ≥30 or a history of morbid obesity.