Exercises With Optimal Scapulothoracic Muscle Activation for Individuals With Paraplegia.

Area of Science:

• Biomechanics
• Exercise Physiology
• Rehabilitation Science

Background:

• Individuals with paraplegia often experience trunk and postural control deficits, increasing reliance on upper extremities and risk of shoulder pain.
• Shoulder pain in this population is multifactorial, involving impingement of rotator cuff tendons and subacromial bursa due to anatomical and kinematic alterations.
• Targeting serratus anterior (SA) and lower trapezius (LT) activation is crucial for maintaining optimal shoulder alignment and minimizing impingement during functional activities.

Purpose of the Study:

• To identify exercises that maximize serratus anterior (SA) activation while minimizing the upper trapezius (UT) to SA activation ratio.
• To identify exercises that maximize lower trapezius (LT) activation while minimizing the UT to LT activation ratio.

Main Methods:

• Ten individuals with paraplegia performed four exercises: "T," scaption, dynamic hug, and SA punch.
• Kinematic and muscle activation data were collected and normalized by maximum voluntary isometric contraction (MVIC).
• One-way repeated measures ANOVA was used to analyze differences in muscle activation and ratios between exercises.

Main Results:

• The SA punch exercise yielded the highest SA activation and the lowest UT:SA ratio.
• The "T" exercise resulted in the highest LT activation, but the SA punch and dynamic hug exercises showed the lowest UT:LT ratios.
• Significant differences in muscle activation and ratios were observed between exercises (p < .05).

Conclusions:

• The SA punch exercise is most effective for maximizing SA activation and minimizing impingement risk.
• Supine exercises, such as the SA punch and dynamic hug, appear more effective in minimizing UT activation.
• Individuals with impaired trunk control may benefit from initiating SA strengthening exercises in a supine position to optimize shoulder mechanics.