Group 1

Precision-Guided Musculoskeletal Engagement:
  1. Commence by establishing a foundational posture characterized by an erect spinal column to ensure optimal alignment of the vertebral segments. This posture facilitates the unimpeded transmission of neural commands from the central nervous system to the targeted musculoskeletal units.
  2. Engage in a preparatory mental rehearsal of the upcoming biomechanical action, focusing on the sequential activation of muscle groups required for the task. This cognitive process aids in optimizing motor unit recruitment patterns for the task at hand.
  3. Activate the primary movers involved in the upper limb elevation: the deltoid muscle (anterior, middle, and posterior fibres) for initiating and sustaining the lift, and the supraspinatus muscle for stabilizing the glenohumeral joint. Concurrent activation of the trapezius and serratus anterior muscles is essential for scapular rotation and stability, facilitating a synergistic elevation of the arm.
  4. Gradually initiate the concentric contraction of the deltoid muscle, ensuring a smooth transition from a state of muscular rest to active engagement. This action is to be synchronized with a controlled extension of the elbow joint, mediated by the contraction of the triceps brachii, while maintaining an isometric contraction of the forearm flexors to stabilize the wrist.
  5. Throughout the elevation phase, the rotator cuff muscles (supraspinatus, infraspinatus, teres minor, and subscapularis) must maintain a balanced level of tension to ensure the humeral head remains cantered within the glenoid fossa, preventing impingement or displacement.
  6. Elevate the upper limb until it achieves a vertical orientation relative to the torso, with the hand positioned directly above the shoulder joint. This terminal position represents the culmination of a precise coordination between muscular contractions and skeletal alignments, achieving a biomechanically efficient posture for maximal limb elevation.
  7. Upon reaching the peak of the movement, sustain the limb in the elevated position, ensuring that muscular engagement is maintained uniformly to prevent unintended movements. This static hold phase emphasizes the control and stability of the musculoskeletal system under conditions of sustained isometric tension.
  8. Conclude the movement by carefully reversing the sequence of muscular activations, allowing for a controlled descent of the limb back to the initial position. This phase requires a meticulous deactivation of the previously engaged muscle groups, ensuring a smooth transition back to the posture of origin without compromising the integrity of the musculoskeletal structures involved.