Continuing with Part 2 of this series, we will address the stabilization requirements for the Olympic lifts. As alluded to in the previous section, stabilization and flexibility must go hand-in-hand. Flexibility allows for increased range of motion (ROM) about the joints, which must be controlled through joint stabilization.
Stabilization of the human body is a dynamically integrated process. This means that it requires many muscles/tissues with different mechanical advantages, tensile strengths and activation thresholds to work together to simultaneously stabilize and move the human body. For those of you who have performed Olympic lifts – or if you have read the previous section in this series – it is easy to see how much joint motion must take place in order to perform these exercises correctly. This is important to note for a couple of reasons:
- Optimal joint motion requires proper length-tension relationships of the muscles affecting that joint (discussed in the last section).
- Every movement of the extremities alters the body’s center of gravity. In order to maintain a solid foundation for proper movement to occur, this must be accounted for by the core musculature.
Each of these concepts will be reviewed in detail next.
Optimal Joint Motion and Proper Length-Tension Relationships
Length-tension relationship refers to the length at which a muscle can produce the greatest force. 1,2 There is an optimal muscle length at which the actin and myosin filaments in the sarcomere have the greatest degree of overlap. This results in the ability of myosin to make a maximal amount of connections with actin and thus results in the potential for maximal force production of that muscle. Lengthening a muscle beyond this optimal length and then stimulating it is believed to reduce the amount of actin and myosin overlap and reduce force production. Similarly, shortening a muscle too much and then stimulating it is believed to place the actin and myosin in a state of maximal overlap and allows for no further movement to occur between the filaments and reduces its force output. 1 , 2
This concept is vitally important to joint alignment and motion as seen in Figure 1. Just as the position of one joint can drastically affect other joints, it can also affect the muscles that surround the joint. If muscle lengths are altered then they will not be able to generate proper force to allow for efficient movement. 1,2,3,4 This results in reciprocal inhibition, synergistic dominance and ultimately joint dysfunction . 5,6,7,8
Figure 1. The effects of muscle imbalance on movement.
Reciprocal Inhibition is a normal neurophysiological process that occurs every time we move a joint. 2 However, the reciprocal inhibition we refer to here is dysfunctional due to altered sensory input into the nervous system caused by muscle (length) imbalances and altered joint motion occurring during movement. In essence, it is muscle inhibition caused by a tight agonist, which decreases neural input to its functional antagonist 5-7,9-15 For example, a tight iliopsoas (hip flexor) will cause decreased neural control of the gluteus maximus (hip extensor). If muscles of a single joint have decreased ability to fire with the appropriate intensity at the right time, then neither that joint nor the entire kinetic chain can optimally stabilize.
Synergistic Dominance is the neuromuscular phenomenon that occurs when synergistic muscles take over function for a weak or inhibited prime mover. 7 , 8 Think of this as your body’s substitution system. When the starting player on a sports team gets tired, the coach puts in the back-up player. The back-up player can perform the tasks necessary to play, but not quite as good or effectively as the starter. The nervous system reacts in the same manner. For example, when the iliopsoas is tight and reciprocally inhibits the gluteus maximus, the biceps femoris and adductor magnus (synergists in hip extension) must activate to perform hip extension (in place of the weakened gluteus maximus). This causes faulty movement patterns (see the last section of this article), which leads to joint dysfunction, tissue fatigue and eventually injury (Figure 1 ).16
Joint Dysfunction is a biomechanical and neuromuscular situation where the forces at the joint are altered, resulting in abnormal joint movement and faulty proprioception. 3-7 Because muscles have altered length-tension relationships and force-couple relationships, they affect the joint in an unnatural manner. If the biceps femoris is working harder to compensate for a weakened gluteus maximus, more force will be placed on the pelvis and knee joint (where it attaches), which can lead to low back and/or knee pain. 17 This pain will alter sensory input to the nervous system, which will further alter muscle recruitment and decrease the stabilization of the kinetic chain. 3-7
Movement and the Core
When we look at the amount of total body movement that occurs with the Olympic lifts, it is very important to realize that all movement begins and ends with the core. 18-21 The core has been defined as the lumbo-pelvic-hip complex (lumbar spine, pelvis and hip region), thoracic and cervical spine. 3 , 4 ,22 In other words, the core consists of everything but the arms and legs. As the arms and legs are directly attached to the core, any time they move the core must counter with the proper muscular activation to maintain a solid base of support from which the limbs can work. This is accomplished by the interaction of many muscles that have been conveniently separated into two interdependent sub-systems 23,24 termed here the Stabilization Mechanism and the Movement System (Table 1).
Table 1 - Muscles of the Core
- Transversus Abdominis
- Internal Oblique
- Lumbar Multifidus
- Pelvic Floor Muscles
- Latissimus Dorsi
- Erector Spinae Iliopsoas
- Tensor Fascia Latae
- Rectus Abdominis
- External Oblique
- Retus Abdominis
To properly execute the Olympic lifts (or any exercise for that matter), the core must operate as an integrated functional unit, whereby the stabilization mechanism works in concert with the movement system. As the foundation and origin of all movement, the core must be structurally sound to allow for the appropriate amount of force production, reduction and dynamic stabilization. This is to ensure that forces are distributed in an efficient manner. 3,4,25 When working optimally, each structural component distributes weight, absorbs force and transfers ground-reaction forces. As such, these interdependent systems must be trained appropriately to allow the kinetic chain to function efficiently during dynamic activities such as Olympic lifting. This means that we must work from the inside (stabilization mechanism/core) out (movement system/limbs) because the stabilization mechanism provides direct stabilization for the lumbo-pelvic-hip complex and the movement system does not. Therefore training the muscles of the movement system (limbs) prior to the muscles of the stabilization mechanism (core) would not make structural, biomechanical or logical sense. Thus the importance of ensuring proper stabilization before performing the Olympic lifts.
Let’s now take a look at the stabilization requirements that would be needed for the Olympic lifts. Since the core is the center and beginning of all movement, we will focus on the LPHC and demonstrate how dysfunction can emanate outward from there, moving up to the shoulder region and cervical spine and downward to the ankle/foot complex.
Lumbo-Pelvic-Hip Complex (LPHC)
- As previously mentioned, this region is the center of all movement,18-21 consisting of approximately 30 muscles on either side26,27 that all must have the appropriate lengths and the ability to properly activate. This region sets the foundation for optimal stabilization of the entire kinetic chain – the lumbar and thoracic spine, shoulder girdle and cervical spine as well as the hips, knee, ankle and foot.
- The LPHC requires optimum levels of stabilization during ALL aspects of the Olympic lifts. First and foremost, it ensures stabilization of the structures that surround the spine providing maximal sensory input to the nervous system, which in turn allows maximal output (motor response or movement). The primary muscles that stabilize the spine (Stabilization Mechanism) and muscles that provide assistance while acting as ‘movers’ (Movement System) can be seen in Table 1.20,23-27 Weakness in the stabilization muscles causes more stress on the joints and synergistic dominance in the movement muscles to help stabilize.5-8 This decreases both muscle groups’ capacity to perform the desired task (Figure 1).
- Weakness in the stabilization mechanism of the LPHC can lead to many important alterations. It is important to note that the following information is a very simplified, general overview of kinetic chain breakdown and is not intended to provide the reader with a full comprehensive analysis. Many of the following situations will occur asymmetrically in the body and therefore require a specific assessment process and exercise program. For complete information on assessments, please refer to the National Academy of Sports Medicine (NASM) at www.nasm.org. For detailed client profiling procedures, see the Profiling Corner of PTontheNET.com.
For each of the following points, please refer to the noted section in Part 2 of this article.
If proper stabilization does not exist in the LPHC the following can occur:
- Synergistic dominance of the iliopsoas and erector spinae to help stabilize the spine. This will cause hyperextension of the lumbar spine (and an anterior pelvic tilt) during the lifts, increasing stress to the low back, hips, thoracic and cervical spine.
- Synergistic dominance of the latissimus dorsi, adductors and rectus femoris and/or hamstring, external oblique, rectus abdominis to help stabilize the pelvis. Refer to the “Hip” table shown in Part 2a of this article for further details regarding altered movement patterns.
- The latissimus dorsi also directly affects shoulder movement, resulting in inhibition of the rotator cuff and scapular stabilizers (rhomboids, lower trapezius, serratus anterior) due to altered joint function (see Figure 1). This leads to synergistic dominance of the upper trapezius, pectoralis minor/major, levator scapulae and SCM, which all further alter shoulder, thoracic and cervical motion during the lifts and sustain inhibition to scapular stabilizers. Refer to the “Shoulder" table.
- The adductors and rectus femoris also cause reciprocal inhibition to the gluteus medius (abductors) and maximus (extensor/external rotator), which can lead to synergistic dominance of the tensor fascia latae (not previously mentioned), piriformis, vastus lateralis, gluteus minimus (not previously mentioned), hamstrings, soleus, peroneals and gastrocnemius to help stabilize the hip, knee and ankle/foot. This increases stress to the low back, hip, knee and ankle/foot complex. Refer to the “Hip,” “Knee,” and “Ankle" table.
The issue with many people who perform Olympic lifts (or lifting in general) is that they are not properly prepared for the high levels of core stabilization/strength and/or flexibility that are required to safely and effectively perform these exercises. The body’s stabilization system (starting with the core) has to be operating with maximal efficiency to effectively utilize the strength, power, neuromuscular control, and muscular endurance that has been developed in the prime movers. If the prime mover muscles are strong but the stabilizing muscles are weak, the kinetic chain will sense imbalance and forces will not be transferred or utilized properly. This will ultimately lead to compensation, synergistic dominance and inefficient movements (Figure1).3,4,8,20,22,25,27,29
Again, the problem is not the lifts themselves or that people shouldn’t do them. The problem is the process that is used to determine who should do them and at what level they should begin their training regiments in preparation for these lifts. Preparing for Olympic lifts requires a systematic programming scheme that incorporates a comprehensive ROM and stability assessment and then flexibility, stabilization, strength and power training that all progress the client toward their goal in an organized planned manner. The Optimum Performance Training™ (OPT™) model was designed by NASM specifically to fulfill this need. This will be touched on in more detail in Part III of this series, (for a detailed exploration, see Mike Clark’s PTontheNET.com article series Essentials of Integrated Training). Part 3 of this series will also focus on some integrated solutions to the second of the two Olympic lifting questions: "Are there safer alternatives to Olympic lifting that are as effective?"
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