Elsevier

Physical Therapy in Sport

Volume 20, July 2016, Pages 40-44
Physical Therapy in Sport

Original research
The development and reliability of a simple field based screening tool to assess core stability in athletes

https://doi.org/10.1016/j.ptsp.2015.12.003Get rights and content

Highlights

  • The adapted core stability test is a quick and simple field based screening test.

  • The test aims to further subdivide athletes with high levels of core stability.

  • Excellent inter-tester reliability with a high ICC and narrow 95% CI was noted.

  • Good to excellent intra-tester reliability with a wide 95% CI was found.

  • Further familiarisation sessions prior to testing may be required.

Abstract

Objectives

To adapt the trunk stability test to facilitate further sub-classification of higher levels of core stability in athletes for use as a screening tool. To establish the inter-tester and intra-tester reliability of this adapted core stability test.

Design

Reliability study.

Setting

Collegiate athletic therapy facilities.

Participants

Fifteen physically active male subjects (19.46 ± 0.63) free from any orthopaedic or neurological disorders were recruited from a convenience sample of collegiate students.

Main outcome measures

The intraclass correlation coefficients (ICC) and 95% Confidence Intervals (CI) were computed to establish inter-tester and intra-tester reliability.

Results

Excellent ICC values were observed in the adapted core stability test for inter-tester reliability (0.97) and good to excellent intra-tester reliability (0.73–0.90). While the 95% CI were narrow for inter-tester reliability, Tester A and C 95% CI's were widely distributed compared to Tester B.

Conclusions

The adapted core stability test developed in this study is a quick and simple field based test to administer that can further subdivide athletes with high levels of core stability. The test demonstrated high inter-tester and intra-tester reliability.

Introduction

Adequate core stability can be defined as the ability to stabilise the spine through integration of the passive spinal column, active spinal muscles and the neural control unit during daily activities and sporting movements (Hibbs et al., 2008, Liemohn et al., 2005, Faries and Greenwood, 2007). While few studies have conclusively displayed an increased injury rate in those with poor core stability (Zazulak et al., 2007, Leetun et al., 2004), it has theoretically been proposed that poor core stability may affect injury rates as it can cause an unstable proximal base, due to the attachment of load transfer muscles at the spine and pelvis (Bliven & Anderson, 2013). Therefore, when high loads are placed on the body during daily activities and sporting movements, the control of the spine is reduced and the positioning of the spine and lower extremity can be altered which may predispose the player to injury (Bliven and Anderson, 2013, Cowley and Swensen, 2008, Cowley et al., 2009, Nesser et al., 2008).

No gold standard core stability test for use in a pre-participation screening, is available at present, and various core stability tests are proposed including: the front abdominal power test (FAPT), side abdominal power test (SAPT), McGill protocol isometric flexor endurance, McGill protocol isometric extensor endurance, McGill protocol isometric side bridge, plank to fatigue, double leg lowering test and trunk stability test (Cowley and Swensen, 2008, McGill et al., 1999, Cowley et al., 2009, Krause et al., 2005, Cook et al., 2006). However, these tests are not considered ideal for use in a screening for a number of reasons. Firstly the FAPT and SAPT tests measure core strength, despite Cowley and Swensen (2008) stating they are a measure of core stability. The isometric McGill and plank to fatigue tests are completed in a single stationary position, which does not reflect the demands placed on the core during most sporting movements (Nesser et al., 2008) and also take a significant amount of time to complete. The tests also have vague or unclear scoring systems and can require expensive equipment or necessitate therapists to develop or build equipment, particularly the double leg lower test, and McGill isometric flexor and extensor endurance tests. The development of a gold standard test for core stability is challenging because not only is there no widely accepted conclusive definition of core stability, there are numerous different muscles that assist in core stability and the interaction between the muscles of the lumbo-pelvic-hip is complex, hence it is difficult for researchers to develop a single test that incorporates all muscles and structures (Cowley and Swensen, 2008, Cowley et al., 2009, Hibbs et al., 2008). Despite these challenges, there is a clear need to develop a quick, simple, valid and reliable test to accurately establish core stability in a participant, which can be easily administered by therapists and utilises minimal inexpensive equipment.

The trunk stability push up test is one of the seven tests utilised to assess fundamental movement in the Functional Movement Screen (FMS™) (Cook et al., 2006). It is proposed that the trunk stability push up test measures reflex core stabilisation and requires participants to complete a closed kinetic chain, upper body symmetrical pushing movement (push up) while controlling and limiting movement of the spine and hips in the sagittal and anterior/posterior plane (Cook, 2010). Thus, it assesses core stability under functional loading during dynamic movement, which is beneficial as dynamic motion occurs during sporting movements and therefore is more applicable for use in a screening or clinical setting (Bliven and Anderson, 2013, Chorba et al., 2010). In addition this test requires minimal equipment and can easily be administered in a field based setting by therapists. While this test has some obvious advantages (quick to administer, requires no equipment, easy to implement, dynamic nature of the test), the trunk stability push up test may not be sensitive enough to differentiate between the subtle differences between good and excellent core stability, especially in the athletic population where core stability is seen by many coaches and athletes as advantageous. It has been demonstrated that 76.2% of young physically active males achieved the highest rating of three in this test (Schneiders, Davidsson, Hörman, & Sullivan, 2011), therefore when implementing a screening with athletes, it may be difficult to sub-classify those with higher levels of core stability utilising this trunk stability push up test. Butler, Plisky, and Kiesel (2012) attempted to increase the precision of the FMS, and generated the 12 point scoring for the trunk stability push up test, with the previous rating of 3, 2 and 1 equalling a score of 12, 5 and 0 respectively. However, the addition of an extra level to this test in order to incrementally challenge the core stability of an athlete may allow further subdivision of the grading system and so identify those with higher core stability. Slightly reducing the base of support to cause light to moderate instability during the test, may require the core muscles to further stabilise and so implement a greater challenge to the participant (Stanton et al., 2004, Haynes, 2004). Thus the aim of this study was to adapt the trunk stability push up test in order to make the test more challenging to the athletic population and allow further differentiation between good and excellent scores.

The reliability of this adapted test is critical in order to accurately interpret the results of this test. Establishing both the inter-tester reliability (the amount of agreement between measurements taken by different testers) and intra-tester reliability (consistency of a tester to capture the same test result when repeated across testing sessions) is important to ensure any improvement or deterioration of core stability noted in the test is not due to the unreliability of the test itself. Therefore the current study aims to establish the inter-tester and intra-tester reliability of this adapted test.

Section snippets

Development of test

The four authors of the study (a clinical biomechanist, a sports medicine physician and two certified athletic rehabilitation therapists), with extensive experience in the clinical and screening setting, adapted the trunk stability test to design the “alternative trunk stability push up test”. Content validity was established by holding a number of meetings to discuss methods of adapting the trunk stability push up test in order to introduce an increased level of difficulty to this test, while

Results

The descriptive results for each tester in session 1 and session 2 are presented in Table 2. An excellent ICC value was observed for inter-tester reliability and a good to excellent ICC value was found for intra-tester reliability (Table 3). While the 95% CI were narrow for inter-tester reliability, Tester A and C 95% CI's were widely distributed compared to Tester B.

Discussion

The current study found excellent inter-tester reliability with a very high ICC value of 0.97 and a narrow 95% CI 0.92–0.99 of the alternative trunk stability push up test. Good to excellent intra-tester reliability with high ICC values (0.73 [95% CI: 0.18–0.91], 0.90 [95% CI: 0.67–0.97], 0.79 [95% CI: 0.27–0.94]) was noted, however the 95% CI were widely distributed for Tester A and C. As the alternative trunk stability push up test was adapted by the authors of this study, comparisons in this

Conclusions

In conclusion, the alternative trunk stability push up test adapted from the trunk stability push up test is a quick and simple field based test to administer during mass screenings that can further subdivide athletes with high levels of core stability. The test demonstrated high inter-tester and intra-tester reliability when therapists are provided with sufficient training in the test. To further improve inter-tester reliability, the addition of a further familiarisation session may be

Conflict of interest

None declared.

Ethical approval

Ethical approval was granted by Dublin City University Ethics committee.

Funding

This study was supported by Professional Development funding by Athlone Institute of Technology and the Irish Research Council for Science, Engineering and Technology (IRCSET) “Embark Initiative” grant.

Acknowledgements

I would like to thank Anna Postawa and Michael Donohoe for their valuable assistance during the testing sessions.

References (27)

  • W. Haynes

    Core stability and the unstable platform device

    Journal of Bodywork and Movement Therapies

    (2004)
  • D.A. Krause et al.

    Abdominal muscle performance as measured by the double leg-lowering test

    Archives of Physical Medicine and Rehabilitation

    (2005)
  • S.M. McGill et al.

    Endurance times for low back stabilization exercises: clinical targets for testing and training from a normal database

    Archives of Physical Medicine and Rehabilitation

    (1999)
  • D.G. Altman

    Practical statistics for medical research

    (1991)
  • G. Atkinson et al.

    Statistical methods for assessing measurement error (reliability) in variables relevant to sports medicine

    Sports Medicine

    (1998)
  • K.C.H. Bliven et al.

    Core stability training for injury prevention

    Sports Health: A Multidisciplinary Approach

    (2013)
  • R.J. Butler et al.

    Interrater reliability of videotaped performance on the functional movement screen using the 100-point scoring scale

    Athletic Training and Sports Health Care

    (2012)
  • R.S. Chorba et al.

    Use of a functional movement screening tool to determine injury risk in female collegiate athletes

    North American Journal of Sports Physical Therapy: NAJSPT

    (2010)
  • G. Cook

    Movement: Functional movement Systems: Screening, assessment, corrective strategies

    (2010)
  • G. Cook et al.

    Pre-participation screening: the use of fundamental movements as an assessment of function–Part 2

    North American Journal of Sports Physical Therapy: NAJSPT

    (2006)
  • P.M. Cowley et al.

    Age, weight, and the front abdominal power test as predictors of isokinetic trunk strength and work in young men and women

    The Journal of Strength & Conditioning Research

    (2009)
  • P.M. Cowley et al.

    Development and reliability of two core stability field tests

    The Journal of Strength & Conditioning Research

    (2008)
  • M.D. Faries et al.

    Core training: stabilizing the confusion

    Strength & Conditioning Journal

    (2007)
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