I must admit, that this site is one of the most complete one I've ever seen. But some of the exercises depicted have serious flaws to them.
Take for example
the stiff-legged deadlift. In the clip, the individual loses his lordosis during the lowering of the bar. This will only ensure ligaments being stretched and create greater instability in the lumbar region.
Same applies for the Seated Row. Leaning over while returning puts the stress solely on the ligaments of the spine since the musculature is relaxed.
Also, the incline sit-up can also create some pressure unto the lumbars from the Psoas muscle. Having your feet anchored active the movement from the origin rather than the insertion.
One last suggestion, would be the exercises for low back and recuperation. Most low back problem are caused from lack of flexibility/muscular lateral imbalance. Working the core stability and flexibility rather than weight training would be most beneficial for those people. I'm sure you can relate to these issues and hopefully make corrections. After all, its for everyone's good.
Concerned visitor (Bsc. Kin., PFLC)
Concerned visitor,
Muscular imbalance and inflexibilities may be attributed to injury, but the causes of lower back injury are poorly understood (Nelson 1993). Although the views you express are popular, I used to hold similar beliefs, other authorities and I disagree with this oversimplified theory. These generalizations are in contrast certain peer refereed journals, academic texts, empirical evidence, and my professional experiences.
Common Beliefs
Commonly held beliefs on the causes of injury are often not supported by scientific studies.
For example, a past colleague performed an exhaustive review of the scientific literature on the problems associated with hyperextension of the lumbar spine during the Powerlifting-style bench press. He found no studies remotely demonstrating problems with this posture despite commonly held beliefs in the exercise community.
Even the idea flexibility exercise decreasing injury has been questioned by recent studies and meta-analyses. See Stretching and Flexibility. Certainly certain individuals may need to improve their flexibility in particular joints, yet others may be found to have too great of flexibility through certain joint articulations. To suggest flexibility training should be prescribed over strength training is a gross overgeneralization. Strength training has been shown to be very beneficial in physical therapy and injury reduction. Just look up the studies listed below (see references) and the many others in listed on PubMed.
It is interesting that many orthopedic surgeons denounce certain commonly performed exercises. For example, some physicians condemn squats citing how destructive they are to the knees despite scientific studies and millions of personal experiences to the contrary. It is undeniable that people can hurt themselves on any exercise, more some than others, but the issue is much more complex than the exercise itself.
Poor form, faulty technique (including altered form due to fatigue), bad program design, insufficient warmup, overtraining, lack of progression (eg: exercise selection, resistance, training volume), and certainly, particular biomechanical deficiencies predisposing individuals to injury are all factors that lead to injury. Also see Causes of Injury.
Incline Situp
During the first portion of the sit up, the abdominal muscles flex the spine. The hip flexor muscles flex the hip to complete the movement. If the abdominal muscles are not strong enough to counter the Psoas' pull on the spine, the lumbar vertebrae can be forced into hyperextension. This can occur during other hip flexor movements as well.
In the book "Strength Training for Young Athletes" by Kraemer and Fleck, the cover states "Includes over 100 safe exercises for 18 muscle groups and 16 sports. They include two sit up exercises with the feet anchored
- Page 105: Bent-Leg Sit-up
- Page 106: Bent-Leg Sit-up with a Twist (on incline)
Steven J. Fleck, PhD and William J. Kraemer, PhD are probably the most well respected scientists studying resistive training. Fleck and Kreamer have dedicated their careers in investigating researching, and writing both scientific and main stream publications on weight training.
Kreighbaum (1996) states: "The physical condition of the performer dictates how safe and effective these exercises will be in the strengthening the abdominal"
For those with no history of lower back pain during hip flexion, situps or leg-hip raises can be considered so the abdominal and hip flexors can be exercised in a single exercise. A determination should be made if the client has adequate abdominal strength to counter the psoas' pull. Like the lower back integrity previously discussed, this biomechanical deficiency can be easily corrected (see links immediately below). Crunches, or half sit ups can be prescribed for the first months before the introduction of hip flexor movements.
Incidentally, the bend of the hip severally diminishes Psoas' mechanical efficiency and consequently its pull on the lumbar spine. See tension potential. Kreighbaum (1996) adds: "For a performer with weak abdominal, the hip-flexed position is the best".
Also see
Flexible hip flexors and strong abdominal muscles are particular important before performing the Decline Situp, Roman Chair Situp, Leg Raises and Hip Raises since the hip becomes fully extended.
As for having your feet anchored effecting movement from the origin rather than the insertion, this essentially does not effect its activation. The muscle contracts through out itself despite the end that moves (origin or insertion). Are the forces through the Latissimus Dorsi some how different in pullup as compared to the pulldown? Your old physics or biomechanics book will clarify the forces are indistinguishable. Incidentally, the crest of the pubis is often referred to as the origin of the Rectus Abdominis, anyway. Obviously, man made classification systems do not perfectly fit all constructs; these semantics merely propitiate rhetorical arguments.
In a horizontal position, the anchoring of the feet will allow you to stabilize the lower body without extending the legs to counter the leverage and momentive forces of the upper body during its extended leverage in the lower position. Remember when the hips are extended the Psoas is activated more. In an incline motion, the anchoring of the feet prevents you from sliding back, or falling on your head.
If a client has such weak abdominal that their psoas is pulling on the back, corrective exercise should be performed months before they start on intense hip flexor exercises. To say sit ups are bad, or any other exercise is bad is a gross over-generalization.
Cable Row
The Cable Seated Row is an excellent movement to condition both the upper and lower back. Even Arnold Schwarzenegger as well as countless other weight trainers perform their cable rows with an articulating spine.
The body adapts to specific stresses placed on the body as long as certain principles are followed. Both the muscles and joint structures can adapt to progressive stresses. Even the elastic limit of a tendon or ligament can be enhanced by exercise and training and can be reduced by aging and inactivity (Tendon and ligament adaptation). Ligaments are not inert.
During the seated row with spinal articulation you say, "Leaning over while returning puts the stress solely on the ligaments of the spine since the musculature is relaxed." In order to relax the muscles of the low back, the exerciser would have to set down the resistance weight and pause. Even if the exerciser deliberately relaxed the musculature with the spine completely flexed, the stretch in the lower back muscles would activate the muscle spindles, or stretch receptors, maintaining an involuntary contraction for several seconds. As with any exercise, moving through the full range of a joint's motion is recommended, yet not beyond.
Ironically, splinting the lower back during all movements can lead to the degeneration of the joint structures of the spine (Nelson 1993, 1995). Including an exercise such as the Cable Seated Row that involves actual (dynamic) movement of joint structures and accompanying muscles are important for lower back integrity. As the saying goes "Use it or lose it". The Cable Seated Row with articulating spine, the Cable One Arm Twisting Row, as well as the Straight Leg Deadlift (below) offer more natural forces to entire kinetic chain as compared to Lever Back Extension and can be implemented progressively for those requiring high degrees of functionality such as certain athletes and manual laborers. It is interesting to note that competive rowers, including athletes at the Olympic level flex their spine throughout the rowing movement. Also see Low Back Debate.
The Cable Straight Back Seated Row has been included for those who desire less lower back involvement during this movement. |