Free Term Paper About Joint Analysis For An Unweighted Squat

Abstract

The focus of the paper is to analyze the motion at three major joints in the body during unweighted squats. The motion at shoulder, hip, and knee is analyzed and the muscles involved are studied. Squats are one of the most frequently used exercises for body strength and conditioning. In order to achieve optimal muscular development, it is helpful to study the squat biomechanics. Therefore, this article discusses the kinematics and kinetics involved in a squat with respect to the knee, hip and shoulder joints.

Introduction

The unweighted squats are also referred to as the body-weight squats and focus on the lower body especially. The prime aim of these squats is muscle growth, and one increases their repetitions in order to make them more challenging. Heavy training with unweighted squats helps one archive sarcoplasmic growth of the muscles mainly. The exercise hits all the main muscles in the legs such as calves, glutes, quads, and hamstrings. When starting out, the unweighted squats will help to increase the size and strength in the muscles.
When doing the unweighted squats, the person stands with his feet shoulder width apart and his hands placed behind his head. This is the starting position, and the movement starts with flexing the knees and hips and sitting down to full depth with the hips. One has to reverse the motion till they return to the starting position. The head and chest should be kept up while pushing the knees out as one squat. The prime muscles involved in a squat are the muscles around the hips and knees, but all joints at the hip, knee, ankle, foot and the spine work together to offer stability and mobility to squat (Andrews, 2015).
The prime focus of the paper is to study the three major joints in the body during the motions in the Shoulder, Hip, and Knee and analyze the motions at the three joints. The Squat can be separated into different phases for proper execution and these include the starting point, which is the Preparation Phase, the Movement Phase comprising of the Descent and Ascent, and lastly the Follow through Phase which is the finish.
Preparation Phase (wind up) Performance of the squat starts with an upright position, knees and hips fully extended. The individual squats down to get the desired squat depth by flexing at the hip, knee, and ankle joints and reverses the direction and moves back to the upright position.
The musculature involved in the lower-body includes quadriceps femoris, hip adductors, hip extensors and triceps surae. The supporting muscles include the erector spinae, abdominals, trapezius, rhomboids, and many others that work to stabilize the trunk. It is projected that more than 200 muscles get activated during an unweighted squat performance (Schoenfeld, 2010).

The main muscle worked on include the Quadriceps, and other muscles are Glutes, Hamstrings.

The preparatory phase is important for the unweighted squat performance and its movement and includes a few requirements. The chin should remain up, and eyes focused straight ahead.
Shoulder - Shoulder Girdle level up, and trunk stabilization follows. The abdominals tighten along with the spinal extensors to support the spine and maintain a flat back position.

During the Shoulder movements, the Serratus Anterior, Rhomboids, Trapezius Upper and Middle contract concentrically.

For the trunk stabilization, External Obliques, Internal Obliques, Rectus Abdominis are contracting.
There is little movement at the hip and knee during this phase. The actions and movement of above muscles in the upper body are very important when causing the action of the lower body for the Squat.
Movement Phase (the skill)If one looks at the knees and hips during the next phase of the movement, our bodies are well adapted to doing this, and there is nothing damaging in the anatomically normal position. Mankind has been squatting ever since he had knees and hips. All joint actions will work in the next movement, where the body lowers down with thighs parallel to the floor.

Shoulder -

Hip - The descent will include Hip Flexion and during the accent hips will be extended.
The major hip muscles involved during the squat are the gluteus maximus and the hamstrings.
The hip joint is a ball-and-socket joint and allows the articulation between the head of the femur and the acetabulum of the oscoxae. The joint is freely mobile and offers three planar movements. During the squat, hip torques raise in combination with a rise in hip flexion, thus making for maximal torque getting created during the bottom phase of movement.
Knee – The descent will include Ankle Dorsiflexion and flexing at knees. Going back action during ascent will include Knee Extension and Ankle Plantar Flexion.
During the squat, the primary muscles acting are the quadriceps femoris and rectus femoris that create the concentric knee extension and resist eccentric knee flexion (Schoenfeld, 2010).
The knee joint is made of the tibiofemoral that offers sagittal plane movement and is supported by a number of ligaments and cartilage.
Ankle - The action taking place at these joints include dorsiflexion, eversion/inversion, and plantar flexion. The talocrural joint facilitates movement through dorsiflexion and plantar flexion. The ankle complex is known to offer major support and generate power during squats.

Dorsiflexion of the ankle will need Extensor Hallicus Longus, the Peroneus Tertius, Tibialis Anterior and Hallicus Longus to contract concentrically.

The lower body is the main catalyst during the Ascent Phase, and the above muscles will work in synergy so as to allow the body to go from the squatted position to a standing one.

The muscle and actions mentioned will work together to allow one to descend and ascend during the squatted position.

Once the Ascent Phase is over, the Squat enters the follow-through phase.
Follow Through Phase
The Follow through Phase is a repeat of the Preparation Phase, but the actions performed are opposite. The Elbow Extension, Shoulder Girdle, and Wrist return to a neutral position, and once returned to this position, the cycle of unweighted squat gets over. The muscles during the Follow through Phase will include all those muscles and actions during Preparation Phase.
When a study was performed on different unweighting conditions and the knee torques created, it was found that for the weighted condition, smaller ankle angles were found. The decrease in the knee torques also controlled the depth of squat and thus these factors could help understand knee injuries (Fineh).
When investigators measured joint torques created at the hip and knee during squats under differing amounts of anterior knee displacement, it was noticed that the athletes used different stance widths. It has been reported that athletes doing squats with wider stance squats exhibit greater hip flexion and smaller plantar flexion angles as compared to those with narrow stance squats. Similar effects are seen in the hip and ankle moments ((Swinton et al., 2012).
In another study comparing front and back squats, it is seen that the muscle activity is significantly different when ascending and descending during a squat. The front squat is as effective as the back squat but imposes lesser force on the knee. Coaches and fitness professionals can make use of this information in their training protocols so as to minimize stress on certain joints and muscles (Gullett et al., 2009).

Conclusion

The Squat is chiefly a lower body exercise that focuses on the muscles of the lower body. However, the muscles of the upper body are involved to stabilize the body for proper execution. If executed properly, this can be one of the best exercises to include in any exercise routine. Correct way, of performing the exercise, prevents injuries and imbalances, and ensure that the muscles are getting resilient, and one is increasing their overall body strength. For further movement, one can add weight to their squats.
The deep squat has received a great amount of attention in the past few decades because of the nature of the movement and mechanics involved. When Squat mechanics were studied for knee, hip and ankle, between different groups, significant differences were found in the mechanics. The ankle works as the basis of the closed kinematic chain during the deep squat activity. Thus, any instability or limitations at this joint could impact the performance. The hip joint acts as a coupler between the upper extremity and lower extremity and thus plays an important role in the alignment. The hip extension moment relying on gluteus maximus and hamstrings can improve stability during the deep squat at the hip joint. It may be right to assume that an individual who has difficulties doing the deep squat could be because of the rectus femoris muscle affecting the knee (Southers et al., 2010).

References

Andrews, R. (2015). All About the Squat. Retrieved from http://www.precisionnutrition.com/all- about-the-squat
Fineh, A. Effects Of Selected Unweighting Conditions On Knee Torques During Partial Squats While Tethered. Indiana State University, 1(1), 544-577.
Gullett, J. C., Tillman, M. D., Gutierrez, G. M., & Chow, J. W. (2009). A biomechanical comparison of back and front squats in healthy trained individuals. Journal of Strength and Conditioning Research, 23(1), 284-292. doi:10.1519/JSC.0b013e31818546bb
Schoenfeld, B. J. (2010). Squatting kinematics and kinetics and their application to exercise performance. Journal of Strength and Conditioning Research, 24(12), 3497-3506. doi:10.1519/JSC.0b013e3181bac2d7
Swinton, P. A., Lloyd, R., Keogh, J. W. L., Agouris, I., & Stewart, A. D. (2012). A biomechanical comparison of the traditional squat, powerlifting squat, and box squat. Journal of Strength and Conditioning Research, 26(7), 1805-1816.
Southers, C., Scoma, C., Kiesel, K. B., Butler, R. J., & Plisky, P. J. (2010). Biomechanical analysis of the different classifications of the functional movement screen deep squat test. Sports Biomechanics, 9(4), 270-279. doi:10.1080/14763141.2010.539623