The musculoskeletal system is actually a fairly continuous arrangement of tissues designed to function in organized patterns rather than simply isolated muscle groups. It operates via force couples and transfers energy through a reaction chain most often rooted in the ground. Motor unit recruitment only becomes isolated to a muscle group when that muscle group is forced to function in a disconnected fashion, as seen in the preacher curl, leg press, triceps pushdown and whatever other bodybuilding exercise one would like to include. For performance enhancement at all levels it makes much more sense to unite segments of the body rather than disconnect them.

When segments are forced to work together (as they should) the whole system improves. When the segments are isolated, the respective parts are enhanced but the ability of those parts to function systematically is reduced. A common example of this is seen with the leg press and the back extension exercise. A person may do well in the isolated environments but when the squat or deadlift is attempted, the parts, although strong individually, are weak synergistically. Energy transfer is lost at the point of connection which is most often seen at the trunk. The ability of the body to stabilize segments is based on the training tenure of tissue and more specifically the motor units recruited for the job. Unfamiliar force couples limit the force potential of the prime movers because energy is lost along the chain. Therefore, just because a person can leg press a significant amount of weight and use added resistance when performing back extension does not mean they can effectively use that force development in the legs and back to effectively lift objects from the ground when standing or to accelerate the body efficiently when running, throwing, or jumping.

Exercises that utilize combined actions of the upper and lower body enhance the linkage system and improve reaction force transfer. When accelerating a mass, particularly via a ballistic movement, such as throwing a baseball or swinging a golf club, the body transfers energy from one body segment to another to continue the flow of energy. Diminution occurs when the energy from one part dissipates into heat rather than transferring the energy into the object or the manifestation point of the body. A front squat to press exercise demonstrates this point. To accelerate the bar upward over head the body takes reaction force from the ground, transfers it through the ankle, across the knee into the hip; where, if stabilized by postural muscles (transverse abdominis, multifidus) and dynamic stabilizers of the trunk, the energy will reach the shoulders joining the tension created by the anterior deltoids. The energy then must pass through the glenohumeral joint to reach the rigidly hinged elbow where it passes to the wrists, finally acting on the bar. The more stable each segment is along the chain the more efficiently (vertical velocity) the bar is transferred.

Closed chain movements performed bilaterally, unilaterally, symmetrically or asymmetrically, on a wide base or on single foot, all challenge segment transfer. When initiating actions of this nature more familiar and stable movements should be practiced and mastered before additional stress is applied. Back squats lead to overhead squats which lead to numerous other challenges related to velocity, stability, or neuromuscular complexity. The key is identifying the need, matching the stress with the client or athletes ability, and progressing at an appropriate rate toward the goal. Adding too much stress causes sloppy and inefficient movement patterns and may create neuromuscular compensation rather than positive adaptations. If the technique is not performed with proper biomechanics the stress presenting the disruption should be reduced.

The Asymmetrical Single Leg Romanian Deadlift to Snatch is one of number of exercises that demonstrate the use of linkage for improved performance. Although the example is demonstrated at the upper level of the movement spectrum, it clearly identifies the requisite for multiple system interaction. The movement can be performed at a lower level of difficulty by starting from a neutral stance and practicing the single-arm snatch before moving to a single leg one arm snatch. Once these are mastered the single to (opposite) single leg one arm snatch can be performed. Velocity can then be added (with a reduction in weight) for an even more dynamic action. The goal is to reach the functional performance goal while remaining safe and effective at each point in the progression.

Romanian Deadlift to Snatch [Starting Position]	Romanian Deadlift to Snatch [Mid-Phase]

Romanian Deadlift to Snatch [End Position]	Romanian Deadlift to Snatch [Alternate Ending] (Hop to Opposite Leg)