Preventing Injuries Before They Ruin Your Routine: Part 9
by Fred Dimenna

Training lower body with an existing knee injury requires an understanding of the problem at hand. Quite often, guys avoid training legs altogether, focusing all attention on upper body and ignoring every muscle below the waist while women continue to train legs, but opt for training poundage that presents virtually no challenge to their neuromuscular system. As a result, the benefits of improved knee health secondary to a stronger surrounding musculature are not realized.

The severity of a knee injury should dictate the appropriate training protocol. If the injury is in its acute stage, it is often necessary to avoid all exercise temporarily. Once activity can be resumed, a progressive approach should be followed, introducing exercises from most to least conservative.

At the most conservative end of the spectrum are strengthening movements that involve little or no movement at the knee. These carry little risk and can be used to at least maintain the current level of conditioning until more aggressive methods can be resumed. For those who had not been exercising prior to the injury, these might actually be appropriate for inducing positive adaptations.

Strengthening the muscles that cross the knee and contribute to its integrity is the objective when rehabilitating an injury. The four muscles of the front thigh (collectively called the quadriceps) are critical. Of these, three cross the knee only and function exclusively to straighten it. The fourth (rectus femoris) also crosses the hip, so it can be trained by moving the thigh.

The rectus functions at the hip to draw the thigh forward (flexion). As a result, straight leg raises target this muscle. These can be done either standing or while lying supine. The latter version is more difficult because leverage conditions create a greater resistive load. In addition, ankle weights can be used to challenge the muscle further.

Just like straight leg raises to the front target a muscle of the front thigh, a similar motion performed to the rear works the two-joint hamstrings. Again, this allows important muscles that cross the knee to be targeted without movement at the joint. Side-lying straight leg raises, both toward and away from the body's midline, work the muscles of the inner and outer hip and round out this protocol.

Because leg raises might not present much of a challenge to well conditioned exercisers, efforts should be made to make them as difficult as possible. These include not allowing the leg to set down between reps, initiating the concentric (lifting) phase slowly to minimize momentum and spending more time raising and less time lowering the leg. A concerted effort should also be made to keep the target muscle(s) contracted throughout the set.

Another popular rehab exercise allows all four quadriceps muscles to be trained with minimal motion at the knee. Quadsets are initiated with the straightened leg supported, as would be the case if you were sitting on the floor. In this case, the relaxed quads are maximally contracted, causing the triangular space between the knee and the floor to be reduced. This contraction is held momentarily, then the leg is again relaxed before subsequent reps are performed. Because the angle at the knee changes slightly when the leg is straightened, quadsets do not qualify as an isometric movement per se, but they are still extremely safe when joint injury is present.

Once more movement can be undertaken, additional exercises can be added to intensify training efforts. While most exercisers think of knee extensions as the exercise performed on the machine at the gym, there are actually other versions that can be used in the rehab setting. The most conservative is a terminal knee extension where movement range is limited. In this case, the individual lies supine with a bolster positioned under the knee so that the knee is partially flexed. From this position, the leg is straightened and the fully contracted position held momentarily before the leg is lowered in a controlled fashion. Again, the quads should not be relaxed between reps; movement should continue throughout.

Once terminal knee extensions are mastered, ankle weights can be added and greater ranges of motion attained. Care must be taken, however, because there is an inherent danger. In other words, instead of the resistance being placed against the bottom of the foot, which would cause the force to compress the joint, it is positioned at a right angle to the limb. This creates a dislocating force at the knee the lower leg is pushed down in relation to the thigh when the leg is extended horizontally. Because ligaments function to hold bones together at joints, a shear force applied when ligamentous laxity exists can be particularly problematic.

Fred DiMenna, a Certified Strength and Conditioning Specialist and Lifestyle and Weight Management Consultant, is a two-time Natural Mr. United States and a WNBF drug-free professional bodybuilder. Visit him on the web at or email him at: