Anatomy Of Human Motion Lab Prosection Critique

Anat062l1 Anatomy Of Human Motion Lab Prosection Critique6for Eac

Anat062l1 – Anatomy of Human Motion Lab – Prosection - Critique 6 For each exercise involving the KNEE joint ONLY, label the type of contraction and the Plane of Motion occurring for each phase of the movement, then list the agonist(s) and Axis of Rotation (prime movers) primarily responsible for causing/controlling those movements for each phase. Beside each muscle in each movement indicate the type of contraction as follows: I-isometric; C-concentric; E-eccentric. There are video hyperlinks of the exercises to ensure you understand the movement occurring.

DUE FRIDAY December 7, 2018

Initial movement (lifting) phase

Secondary movement (lowering) phase

Paper For Above instruction

The analysis of knee joint movements during various strength training exercises provides valuable insights into the biomechanical functions involved. This critique will systematically identify the characteristics of muscle contractions—whether concentric, eccentric, or isometric—as well as the planes of motion for each movement phase. Furthermore, it will specify the primary agonist muscles and the axes of rotation responsible for controlling these movements, offering an in-depth understanding of knee joint biomechanics in common training exercises.

Sissy Squat

During the sissy squat, the knee joint primarily undergoes a combination of flexion and extension, occurring predominantly in the sagittal plane. During the lowering phase, the quadriceps femoris act eccentrically (E) to control knee flexion as the body descends forward, stabilizing the movement against gravity. The axis of rotation is the mediolateral axis passing through the knee joint. The main agonist during this phase is the quadriceps group—vastus lateralis, medialis, intermedius, and rectus femoris—acting eccentrically to control flexion.

In contrast, during the return to starting position, the quadriceps contract concentrically (C) to extend the knee and raise the body. The primary agonists are the quadriceps muscles, executing an isotonic concentric contraction, while the axis remains unchanged. The movement occurs mainly in the sagittal plane, with the quadriceps stabilizing the tibia relative to the femur.

Glute Ham Raise

During the lowering phase of the glute ham raise, the hamstring muscles—biceps femoris, semitendinosus, and semimembranosus—perform an eccentric contraction (E) to control the hip and knee flexion, decelerating the descent in the sagittal plane. The axis of rotation is centered through the knee joint, allowing flexion and extension movements. The primary agonists are the hamstrings, controlling movement eccentrically. Conversely, during the ascent phase, these muscles contract concentrically (C) to extend the knee and extend the hip, restoring the body to the starting position.

Vertical Jump

In the vertical jump, the initial downward movement involves eccentric contractions (E) of the quadriceps, glutes, and calves to decelerate the descent, controlled in the sagittal plane. The axis of rotation passes mediolaterally through the knee joint, enabling controlled flexion. During the push-off phase, these muscles contract concentrically (C) to propel the body upward, with prime movers including the quadriceps, gluteus maximus, and calves—particularly the gastrocnemius and soleus muscles—acting concentrically. The movement occurs primarily in the sagittal plane, producing vertical displacement.

The phase of leaving the ground involves explosive concentric contractions (C) of these prime movers, generating the necessary force to overcome gravity and achieve lift-off. The axis remains consistent through the knee joint, emphasizing flexion during descent and extension during propulsion.

Landmine Bulgarian Split Squat

During the lowering phase, hip flexion and knee flexion occur in the sagittal plane, with eccentric contraction (E) of the quadriceps and hamstring muscles. The primary agonists are the quadriceps and hamstrings—particularly the rectus femoris and biceps femoris—performing eccentric control to decelerate movement in the sagittal plane. The axis of rotation is through the knee joint. As the body descends into the split squat position, these muscles stabilize and control the movement.

On returning to the start position, the quadriceps and gluteal muscles contract concentrically (C) to extend the knees and hips respectively, powering the extension phase. These movements, active primarily in the sagittal plane, are controlled by the same axis of rotation at the knee joint.

Hack Squat

The hack squat involves controlled knee flexion during the lowering phase, with eccentric contraction (E) of the quadriceps. The movement takes place in the sagittal plane, with the axis of rotation through the knee joint. The primary agonists controlling deceleration are the quadriceps muscles, especially vastus lateralis and medialis, which oppose gravity. During the ascension or return phase, the quadriceps perform concentric (C) contractions to extend the knee and lift the weight, restoring the joint to its initial position in the sagittal plane.

Conclusion

The detailed analysis of knee joint movements across these exercises demonstrates that, predominantly, movements occur in the sagittal plane with flexion and extension being the principal actions. The muscle contractions vary between eccentric and concentric depending on whether the muscles are controlling or initiating movement. The quadriceps serve as the primary agonists during both lowering and lifting phases, with hamstrings and gluteal muscles providing stabilization or assisting in related movements such as hip extension. The axis of rotation remains consistent through the knee joint, emphasizing the importance of understanding muscular function for safe and effective training.

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