• Hot Topic: Taking Movement Screening a Step Further: Identifying Asymmetries
    Fitness testing, evaluations, and screenings can greatly assist the strength and conditioning coach or clinician in identifying areas of fitness performance that require improvement or maintenance, but can also serve as highly useful tools for identifying possible predispositions to compensatory muscle actions that facilitate poor form and increase risk of injuries.
  • comment 
    Tell us what you think of this article in the new
    "comments" section below.
     
  • Figure running across electrocardiogram lineIntroduction
    Strength and conditioning programs are designed to improve athletic and functional performance and reduce the risk of injury through a progressive, individualized, and population-specific training program. Consequently, the inclusion of corrective exercises and prehabilitation (prehab) programs to address deficiencies or compensational movement patterns that may increase one’s risk for of injury and hinder the optimal development of the athlete has become commonplace in many strength and conditioning programs.

    Corrective exercises, or interventions targeting specific movement dysfunctions, should be based on the results of evaluations (that identify muscle tightness or weakness or poor neuromuscular control), which have been driven by the movement screens that highlight areas of concern and the need for further evaluation.

    There are numerous factors that may increase an athletes’ risk of injury, including but not limited to, muscle imbalances and weakness, poor joint mobility, structural asymmetries (e.g., scapular asymmetry), body misalignment, poor motor control, previous injury and joint stress (obesity) (3,4). Muscle imbalance and/or poor body alignment may result in excessive mobility, poor stability, and weakness in certain muscles from being stretched extensively.

    This may increase reliance on other muscle to facilitate various functions (movement or stabilization), leading to overuse concerns. For example, athletes with kyphosis-lordosis may be more likely to have weak abdominal and gluteal muscles, and tight low back and hip flexor musculature (9).

    Such imbalances may, over time, impact posture as well as force distribution through the kinetic chain, which in turn may contribute to movement inefficiencies, muscle misuse, and consequently dysfunctional training. Further training in this manner may increase the likelihood of further perpetuating any imbalances, increasing risk of injury.

    Identifying Weakness
    Movement screens, form evaluations, postural assessments, and jump assessments, do a great job identifying compensational movement patterns and regions or joints where dysfunction is possibly occurring. However, to identify with confidence where and what the muscle imbalance is often requires further evaluation. Functional movement screens, just like watching form on a given exercise, are not diagnostic tools—they identify possible areas of movement inefficiency across common movement patterns (4,10).

    The dysfunctional factors contributing to these issues may now need to be examined at the joint level or a region of the body (e.g., the pelvic region). Correcting asymmetries at the local level is one of the first steps to take to help decrease compensatory movement during comprehensive multi-joint movements such as squats and lunges (4).

    After completing a functional movement screen that highlights average or poor movement patterns, several questions may need to be addressed prior to prescribing corrective or prehab exercises to target the asymmetries contributing to the compensatory movement seen on the multi-joint movement (e.g., squat). These may include:

    Is the asymmetry due to an imbalance in muscular strength, mobility, stability, or muscle activation? Are all or any of the asymmetries possibly contributing to the compensatory or less than optimal movement identified within the battery of movements conducted as part of the screening? For example, did the athlete score average on a single-leg hamstring raise for the left leg and poor for the right? Or is the poor performance on a hurdle or lunge due to an imbalance in gluteal activation, lower or upper cross syndrome, ankle instability, or some other imbalance not otherwise identified through the movements on the screening?

    It is important that assumptions about what is causing the compensatory movement are not made without evidential support. For example, a client demonstrated forward progression of the dowel (unable to maintain dowel over their head) during an overhead squat conducted as part of a functional movement screen. During the screening, they had shown good shoulder mobility and single-leg raise scores on both sides.

    Given the forward progression of the dowel, further evaluation of glute activation, hip flexor, quadriceps, and ankle dorsiflexion range of motion may be recommended, but it is probably not necessary to evaluate hip adduction if there were no frontal plane hip or knee anomalies (e.g., valgus) on the movement screen. If improper corrective exercise programs are implemented as a result of improper or inadequate analysis, they may risk further magnifying existing problems and compensations, or simply being ineffective and a waste of valuable conditioning time.

    The concept of taking results from a functional movement screen, and then conducting a joint by joint evaluation for possible imbalances may not be a practical or feasible approach for a strength and conditioning coach working with multiple teams (although the recruitment of interns and graduate assistants, as well as collaborative efforts with other professionals such as the athletic trainers and exercise or sports science faculty may help facilitate this approach).

    Therefore, a coach may need to consider what further subset of evaluations to conduct based on the compensatory movements shown in the screen and the disposition to various asymmetries common to specific sports, level of play, and gender. For example, male collegiate volleyball players have an increased susceptibility to range of motion decrements in the internal rotators of the dominant arm, as well as lower concentric external rotator strength relative to the non-dominant arm. However, the strength or the internal rotators in the dominant arm tends to be greater than that of the non-dominant arm. These athletes are also disposed to scapular asymmetries as a result of the physical demands of the sport (9,12).

    Asymmetries in the Body 

    Asymmetries between the right and left sides of the body are common in sports that are dominant on one side of the body, typically specific to the region of the body where the dominance is emphasized (e.g., soccer – lower body/lower back). Common movement patterns identified with screenings do manifest similarly in individuals engaging in similar physical demands.

    This often makes corrective exercise prescriptions that are specific to movement dysfunctions within groups or teams appropriately justified. Based on the results of screenings and evaluations, as well as the aforementioned sport-related knowledge, a strength and conditioning coach or clinician prescriptive may then have the option of working from a simple (less specific or team) pattern-based application to a more specific individually prescribed (tailored) program depending on the available resources.

    Asymmetries may exist between the right and left sides of the body, between agonist and antagonist muscle groups (e.g., hamstring and quadriceps), or between anterior and posterior muscle groups (e.g., upper or lower crossed syndrome) (3,6,8). Therefore, it is important to evaluate as much muscle or joint activity that might be influencing the dysfunctional movement as is possible. For example, lower crossed syndrome suggests there is possible tightness in the thoracolumbar extensors, hamstrings, adductors and/or hip flexors, and weakness in the abdominals, gluteus maximus and medius, and quadriceps (6).

    This may impact degree of pelvic tilt, curvature of the spine, and consequently joint alignment, force translation throughout the kinetic chain, and performance on multi-joint movement patterns in a functional movement screen or training program. A coach may use the Thomas test to evaluate rectus femoris, iliopsoas, and iliotibial band tightness, combined with a sit-and-reach test or Waiter’s Bow to evaluate hamstring tightness, as well as the FABER or Patrick test to examine iliopsoas, sacroiliac or hip muscle tightness, and a gluteal muscle activation test to gage the likelihood of lower cross syndrome.

    The aforementioned tests may also be combined with measures of core endurance, strength, or stability such as the flexor endurance test and Biering-Sorenson back plank test, or right and left side bridges to examine anterior-posterior static muscular endurance. Common approaches used to examine possible asymmetries in stability and mobility throughout the lower extremity may include (but are not limited to) the Y-balance test, the star excursion test, the Bass Balance test, Trendelberg’s test (gluteus medius muscle), and goniometer measures for specific joint flexibility.

    Simple measures such as a single-leg balance, torsional control test, or Sahrmann test for core stability may also provide insight to possible imbalances in addition to the rotational control movement that is part of the functional movement screen.

    Goniometer measures for the shoulder are a common approach for evaluating asymmetry, particularly when comparing right and left sides of the body or opposing actions (internal versus external rotation, flexion versus extension), and may provide additional insight into the specific action of the shoulder that is leading to the imbalance shown during the dynamic shoulder mobility movement that is part of the functional movement screen. Full descriptions of these tests can be found in most reputable screening or assessment-base texts (1,2,4,5,7,11).

    Establishing a baseline measure of the magnitude of imbalance early on in the pre-season can help evaluate the effectiveness of a corrective or prehab program through the season. If improvements do not develop or new compensatory movements are displayed then additional evaluations can be conducted. Further comprehensive evaluations by an athletic trainer, physical therapist or physician may be necessary if the athlete experiences pain during movement or in cases of more severe signs or symptoms of dysfunction (e.g., impingement).

    Conclusions
    Functional movement screens are an excellent starting point for evaluating movement patterns and developing programs to promote optimal posture, stance, kinetics, and kinematics. However, it is an approach that may help to identify dysfunctional movements that might be contributing to, or be a precursor for injury or less than optimal training potential. Therefore, it should not be implemented in isolation.

    Although similar corrective exercises may usually be introduced as part of an injury prevention prehab circuit for an entire team, sometimes the exercises need to be individualized to address concerns not common to the majority of players. These needs will need to be identified through a more comprehensive assessment than screening alone. Movement screens and subsequent joint or regional evaluations should help direct training programs.

    An excellent description of how a combination of movement screening and functional assessment can be used to help guide the design of corrective exercise or prehab programs for collegiate athletes was recently published by Martin Diltz (9).
  • Sell_thumb

    About the Author:

    Katie Sell, PhD, CSCS,*D, TSAC-F

    Katie Sell is an Associate Professor in the Department of Health Studies and Kinesiology at Hofstra University. Her primary research interests lie in the area of physical fitness assessment, programming, and injury prevention for collegiate athletes and wildland firefighters. She is currently on the NSCA Tactical Strength and Conditioning SIG Executive Council and a consultant with FireFit (interagency wildland firefighter fitness task group).

    REFERENCES →

    1. American College of Sports Medicine (ACSM) (2013). Guidelines for exercise testing and prescription (9th ed.). Baltimore, MD: Lippincott, Williams & Wilkins.
    2. Baechle, T.R., and Earle, R.W. (2008). NSCA’s essentials of strength and conditioning (3rd ed.). Champaign, IL: Human Kinetics.
    3. Coombs, R., & Garbutt, G. (2002). Developments in the use of the hamstring/quadriceps ratio for the assessment of muscle balance. Journal of Sports Science and Medicine, 1, 56-62.
    4. Cook, G. (2010). Movement: Functional movement systems. Aptos, CA: On Target Publications.
    5. Heyward, V.H. (2006). Advanced fitness assessment and exercise prescription (5th ed.). Champaign, IL: Human Kinetics.
    6. Jenkins, J.R. (2003). The transversus abdominis and reconditioning the lower back. Strength and Conditioning Journal, 25, 60-66.
    7. Konin, J.G., Wiksten, D.L., Isear, J.A., & Brader, H. (2006). Special tests for orthopedic function. Thorofare, NJ: SLACK Incorporated.
    8. Kritz, M.F., & Cronin, J. (2008). Static posture assessment screen of athletes: Benefits and considerations. Strength and Conditioning Journal, 30, 18-27.
    9. Martin Diltz, M. (2012). Stand up performance. Training and Conditioning, September, 41-46.
    10. McMillian, D. (2013). Hot topic: Functional movement screen. NSCA Hot Topic Series, 1-4.
    11. National Strength and Conditioning Association (NSCA) (2012). NSCA’s guide to tests and assessments. Champaign, IL: Human Kinetics.
    12. Wang, H.K., & Cochrane, T. (2001). Mobility impairment, muscle imbalance, muscle weakness, scapular asymmetry and shoulder injury in elite volleyball athletes. Journal of Sports Medicine and Physical Fitness, 41, 403-410.
     

  • Disclaimer: The National Strength and Conditioning Association (NSCA) encourages the exchange of diverse opinions. The ideas, comments, and materials presented herein do not necessarily reflect the NSCA’s official position on an issue. The NSCA assumes no responsibility for any statements made by authors, whether as fact, opinion, or otherwise. 
  • Add Comment

    Text Only 2000 character limit

    0 Comments

    Page 1 of 1