Biomechanic Activity Analysis
As humans, we move (or should move) constantly throughout our day. As a wife and dog mama, one motion that is constant in my daily life is bending to pick things up. I am always picking up after my husband and pup. When bending over to pick something up, it is important to bend at the knees rather than at the hip to ensure that you do not injure yourself.
The starting position includes standing upright with your feet spread slightly apart so that you have a wide base of support, and make sure that you are close to the object that you are picking up. Then, you will bend (flex) the knees and very slightly bend (flex) at the hip. Again, most of the bending is done at the knees. However, both motions are done in the sagittal plane and frontal axis. Once at a good level, reach forward with your arm(s) to grasp the object. This specific motion is shoulder flexion and is also done in the sagittal plane and frontal axis.
Since we are doing most of the work with our lower extremities, let's discuss in greater detail the flexion movement of the knee joint. The knee joint is considered a hinge joint. According to the convex/ concave rule of arthrokinematics, the femur, which is the convex and moving surface, rolls posteriorly and glides/ slides anteriorly on the tibia, which is the concave, stable surface.
There are several muscles that fire when bending over. You can think of it as a squat. During the downward phase, or flexion, the quadriceps muscles are lengthening, or eccentrically contracting while the hamstring muscles are shortening, or concentrically contracting. This occurs vise versa during the extension, or the upward phase. If there is a pause at any point during your squat, these muscles will be isometrically contracting, that is, not shortening or lengthening. Lastly, when picking up the object, make sure that your core remains tight and you hold it close to your body. Lift using your LE muscles, and do not twist in any way while you are bending, lifting, or carrying the object. The end position includes holding the object in an upright position, free of injuries!
The starting position includes standing upright with your feet spread slightly apart so that you have a wide base of support, and make sure that you are close to the object that you are picking up. Then, you will bend (flex) the knees and very slightly bend (flex) at the hip. Again, most of the bending is done at the knees. However, both motions are done in the sagittal plane and frontal axis. Once at a good level, reach forward with your arm(s) to grasp the object. This specific motion is shoulder flexion and is also done in the sagittal plane and frontal axis.
Since we are doing most of the work with our lower extremities, let's discuss in greater detail the flexion movement of the knee joint. The knee joint is considered a hinge joint. According to the convex/ concave rule of arthrokinematics, the femur, which is the convex and moving surface, rolls posteriorly and glides/ slides anteriorly on the tibia, which is the concave, stable surface.
There are several muscles that fire when bending over. You can think of it as a squat. During the downward phase, or flexion, the quadriceps muscles are lengthening, or eccentrically contracting while the hamstring muscles are shortening, or concentrically contracting. This occurs vise versa during the extension, or the upward phase. If there is a pause at any point during your squat, these muscles will be isometrically contracting, that is, not shortening or lengthening. Lastly, when picking up the object, make sure that your core remains tight and you hold it close to your body. Lift using your LE muscles, and do not twist in any way while you are bending, lifting, or carrying the object. The end position includes holding the object in an upright position, free of injuries!
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