Improving Squat Depth

July 19, 2012 By 2 Comments

By, Sean Light CSCS

SLStrength.com

One of the cues coaches look for when coaching a squat is the pelvic alignment. When squatting, we are taught to tighten your back and try and maintain an anterior tilt of the pelvis. Once the athlete can longer maintain this form, then they have reached their maximum squat depth.

If we want to keep the pelvis in anterior tilt, we must think about what muscles are pulling the pelvis posteriorly. The muscles of the posterior thigh musculature will be the primary pullers here. The hamstrings, specifically the biceps femoris, semitendinosus and semimembranosus, pull the pelvis down from behind the leg. The tighter these muscles are, the quicker in the squatting movement the pelvis will lose its anterior tilt. Thus we must decrease the tension in the muscle in order to increase your squat depth.

It’s also important to recognize the rectus abdominis role pulling the pelvis posteriorly. The rectus abdominis, which is essentially your six-pack, is often overlooked in this process due to its anterior bodily location. However the inferior attachment of this muscle is on the bottom of the pelvis so when this particular muscle is tight, it pulls the pelvis from the bottom and into posterior tilt.

Now we know from my article “Hamstrings and Back Problems are KINECTed” what the tilt of your pelvis can have on the health of your back, so we also know why it’s so important to maintain a proper pelvic tilt throughout the squatting motion. If your technically efficient squat depth is not deep enough, we need to work on the muscle flexibility of these muscles.

PNF Stretching is a great option for increasing flexibility in the hamstrings but can be difficult for the rectus abdominis. Read about PNF Stretching HERE. For your six-pack, some prone press ups will work well. Livestrong.com has few more for you HERE.

  • THE PICTURE DISPLAYS LEBRON JAMES PULLING HIMSELF INTO POSTERIOR TILT (AS WELL AS SOME GOOD T-SPINE FLEXION) WHILE TYING HIS SHOES

SOURCE: http://solacenmt.blogspot.com/2010/11/pelvic-tilt-and-its-effect-on-lower.html

Filed Under: Injury Prevention Tagged With: , , , , , , , , , , , , , , , ,

Biceps Femoris

July 11, 2012 By 1 Comment

By, Sean Light CSCS

SLStrength.com

The first thing we need to realize when discussing the Biceps Femoris is that it is not in your arms, but anatomically we have to note that there are two heads to this muscle, hence “Bi.” One can then safely assume that any triceps muscle will have three heads.

The Biceps Femoris is located on the posterior thigh (the hamstring area) and is responsible, although not solely responsible, for knee flexion (heel to butt), hip extension (moving leg backwards), the lateral rotation of the knee when flexed, and flexing the calf from the knee.

The origin of the  long head of the Biceps Femoris is on the pelvis at the Ischial Tuberosity. The short head originates at the linea aspera of the femur (thigh bone). Because these are the points of origin, all Biceps Femoris muscle contractions will move towards this point.

The insertion point of the BF’s long head is on the head of the fibula which is the smaller of your two shin bones. The small head inserts at the lateral tibial condyle.

It’s important to know that no muscle can actually push. All motion is derived from shortening, pulling muscles. Thus, if the insertion always moves towards the origin, the action of this muscle will always be pulling upwards.

SOURCE: Hosford DPT, Darryl,”Posterior Thigh Musculature,” http://www.PTCentral.com/muscles

Filed Under: Anatomy Tagged With: , , , , , , , , , , , , , , , , , , ,

Shoulder Sulcus Sign

July 6, 2012 By Leave a Comment

By, Sean Light CSCS

SLStrength.com

Shoulder sulcus is a sign of laxity in your shoulder. This video explains how to test for a shoulder sulcus sign.

If the sulcus sign is positive, meaning the the glenohumeral joint (shoulder joint) is indeed loose, you will be able to see an indentation form on their shoulder when performing this test.

From an injury standpoint, this laxity will certainly put you at greater risk of injury. This sulcus sign could be a result of previous injury or gradual wear and tear but it is important to tighten up the ligaments to decrease the laxity. The shoulder already has enough trouble stabalizing with a shallow fossa (socket) and large range of motion.

From a baseball standpoint, increased shoulder laxity can improve your throwing velocity but at the cost of higher injury risk. You can’t throw if you are not on the field so it is more important to tighten up that joint for a more efficient and less dangerous range of motion.

If your shoulder is demonstrating a positive sulcus sign there are some exercises you can do to help. Simple internal (keep your elbow tight to your body) and external rotation exercises, flexion exercises (pushups, front raises), rows, lat pull-downs and scapular mobility exercises.

For a reminder on basic shoulder movement patters, check out my article on the Biomechanics of Baseball Pitching.

SOURCES:

Sawyer PT, Chris, “Rehab of the Unstable Shoulder,” http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&ved=0CEwQFjAA&url=http%3A%2F%2Fwww.childrensmercy.org%2FContent%2FuploadedFiles%2FDepartments%2FGraduate_Medical_Education%2FCME%2FRehabilitation%2520of%2520the%2520Unstable%2520Shoulder.pptx&ei=lBb3T4KGKcnc0QGlhOX4Bg&usg=AFQjCNG7Szx801P5CS2vNPjbP7-5vL2u6g&sig2=bMJSuLEGBc9zFB3uB2UEmg

“All About Shoulder Dislocation,” http://www.ori.org.au/bonejoint/shoulder/diagnosis.htm

“Sulcus Sign,” http://videos.rehabstudents.com/sulcus-sign/

Filed Under: Injury Prevention Tagged With: , , , , , , , , , , , , , , , , , , , , ,

Preventing Injury with Yoga

June 14, 2012 By Leave a Comment

By, Sean Light CSCS

SLStrength.com

Pick up a dumbbell, start with your arms fully extended and attempt a bicep curl. Now, instead of starting with your arms extended, start the arm at a ninety degree angle. The curl is certainly easier when starting with the modified start position. This is because at the end of any given range of motion, the muscle is at its weakest.

In order for a muscle to contract, myofilaments called actin and myosin must connect using cross-bridges within the part of the muscle called the sarcomere. When the muscle is fully contracted, the actin and myosin are too close together to get a maximal amount of connections. Conversely, at the end range of motion, the myofilaments are too far apart to achieve maximal connections. Thus, somewhere in between end range of motion and full contraction is the range for the most cross-bridge connections.

One of the most common ranges for injury to occur is at the end range of motion. In order to better prevent athletes from finding themselves on the disabled list, it’s important to increase strength and the end range of motion.

Traditional weight lifting, assuming proper form is used, strengthens throughout an entire range of motion. Isometric exercises pinpoint one area of the range of motion to strengthen.

Isometric exercises are holds. The athlete locks into one position and holds the position for a given amount of time. Examples are pushup holds, wall sits and pull up holds.

If the strength and conditioning coach properly selects the isometric exercises, he or she can increase the athlete’s strength at the end range of motion and decrease the athlete’s risk of injury at that particular range.

Yoga revolves around “poses,” or positions held for a given period of time. Sound familiar? These poses are isometric exercises. Instituting yoga poses into strength and conditioning program is a great way to help athletes avoid the disabled list.

Filed Under: Injury Prevention Tagged With: , , , , , , , , ,

Hamstrings and Back Problems are KINECTed

June 11, 2012 By 1 Comment

By, Sean Light CSCS

SLStrength.com

Poor hamstring flexibility puts your body at risk and can lead to debilitating back injuries. If the elasticity of the hamstrings is not sufficient, the problem will likely work its way up the kinetic chain, causing more problems and causing vulnerability in your spine.

The kinetic chain is essentially the relationship of various body parts and how they work together to create movement. For example, if you need to bend over and pick something up off of the ground your hamstrings need to be able to stretch. If they are not flexible enough, your body needs to adjust in order to get the object from the floor. Maybe you twist your torso to get closer to the ground, maybe you squat to eliminate the need for hamstring flexibility, or maybe you bend at your back. This final possibility is known as spinal flexion and too much of this will lead to spinal injuries.

Once the hamstrings reach their maximal length, the next thing to change is the pelvis. The pelvis is the bone at your hips and it can tilt in two ways, posteriorly and anteriorly. When lifting off of the ground, you want to maintain an anterior pelvic tilt. This is when the top of the pelvis is tilted forward. This will allow your lumbar spine (the lower section of your spine) to stay in its natural curvature.

The spine has four natural curves. The cervical curvature is at the top of the spine and bends towards the front of your body. The thoracic curvature, at the middle of your back, bends towards your back. Similarly, the lumbar curvature and sacral curvatures bend to the front and back respectively.

If your pelvis creates a posterior pelvic tilt during a lift then it will take your lumbar spine out of its natural form and into spinal flexion. Too much spinal flexion will improperly distribute weight onto your intervertebral discs. When standing, the pressure on your spinal discs equates to 100PSIs. When sitting slouched you create up to 175PSIs of pressure, but when you try to lift a twenty-five pound box off of the ground with too much spinal flexion, you create over 400PSIs of pressure.

This enormous amount of pressure can create injuries such as bulging, ruptured or even degenerative discs. Aside from disc injuries, muscular strains and ligament sprains also increase in possibility when spinal flexion is too great.

A simple test to see if you are at risk for these problems as a result of poor hamstring elasticity would be to stand up, keep your legs straight and touch your toes. Make a mental note of how far down you could go. Then bend down and touch your toes while only hip hinging. Hip hinging is only bending at your hips, or using your hips as a hinge like on a door. While hip hinging, focus on pushing your butt backwards. Most likely, you will not be able to go nearly as far on the hip hinge as you were on the first try. This is because you eliminate the possibility of spinal flexion thus decreasing your total range of motion.

No matter your range of flexibility in your hamstrings, continue to work at its flexibility to maintain and ensure minimal risk of back problems as a result of poor hamstring flexibility.

REFERENCES:

health.rush.edu

http://www.k-state.edu/safety/training/Safe%20Lifting/Safe%20Lifting%20is%20not%20an%20accident-PowerPoint_files/frame.htm

http://www.precisionnutrition.com/all-about-spinal-health

Filed Under: Injury Prevention Tagged With: , , , , , , , , , , , , ,
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