Research in Focus: A new Take on Balance Assessment Following a Sport-related Concussion

  •   March 8, 2018
  •  Thaer S. Manaseer MSc, BScPT, Douglas P. Gross PhD, BScPT, Codi Isaac PT, MScPT, BCom, and Jackie L. Whittaker, PhD, BScPT

Sport-related concussion is a significant health problem amongst Canadian youth (i.e., 10 – 18 years old) due to its high prevalence, and associated consequences. Sport-related concussions result from either a direct or indirect blow to the head, and may cause a wide range of signs and symptoms including, but not limited to; headache, dizziness, confusion, irritability, feeling slow, sleep problems, and/or balance deficits.1 Among these effects of sport-related concussion, balance deficits are the focus of this article.

Impaired balance-control is one of the most common signs of a sport-related concussion with up to 30% of athletes who suffer a concussion demonstrating balance deficits.2 It has been suggested that these deficits stem from an inability to integrate sensory input, ignore changed environmental conditions, or apply the appropriate motor control strategies to maintain balance.2 Therefore, balance examination is an important component of sport-related concussion assessment.1

Currently, the Tandem Gait test and Balance Error Scoring System are the standard clinical balance tests used to examine dynamic and static balance ability after a sport-related concussion respectively.3 The Tandem Gait test involves walking in a forward direction along a 38mm-wide three-meter long line, with an alternating foot heel-to-toe gait as accurately as possible.3 During the Tandem Gait test, patients are scored on their ability to perform the test without stepping off the line, separating their heel and toe, or touching the examiner or an object for support.3 By contrast, the Balance Error Scoring System involves balancing in three stances (double-leg support, single-leg support and tandem) for 20 seconds, with the eyes closed, first on a firm and then on an unstable (i.e., foam pad) surface.4 During the Balance Error Scoring System, patients are scored on their ability to maintain each stance without moving their hands off of iliac crests, opening their eyes, stepping, stumbling, falling, abducting or flexing the hip beyond 30 degrees, lifting forefoot or heel off the testing surface, or remaining out of the proper testing position for greater than five seconds. Both the Tandem Gait test and Balance Error Scoring System are quick to perform, inexpensive, and easy to use in clinical and sports settings.

Although the Tandem Gait test and Balance Error Scoring System represent the current standard, there has been a call for improving methods for assessing balance after a sport-related concussion due to the limited ability of these tests to identify persisting balance deficits.4-6 Our team in the Faculty of Rehabilitation Medicine at the University of Alberta and the Faculty of Kinesiology at the University of Calgary has initiated a new research project that aims to develop and evaluate a new clinical method for testing balance-control recovery status following sport-related concussion. The research consists of three phases, which are described below.

1.    Systematic Review of Gait Deviations Following Concussion

We conducted a systematic review of the existing research to identify the gait deviations most commonly associated with concussion which has recently been published in the Clinical Journal of Sports Medicine.7 The review identified 21 studies that assessed some aspect of balance following a concussion in 1,120, participants (mostly athletes) who ranged in age from five to 53 years. Across these studies gait was assessed with either a single (i.e., gait only), and/or a dual (i.e., gait while carrying out a secondary mental task) gait task. The average time between concussion and gait assessment across the included studies was 14 days (range 24 hours to four years). The most commonly investigated gait parameters identified were gait velocity, magnitude of center of body displacement and center of body displacement velocity.

The main findings of the systematic review were that concussed individuals sway more in the frontal plane and may walk slower compared to non-concussed controls both during the symptomatic (i.e., within 10 days) and asymptomatic (i.e., > 10 days) phases following a concussion. Further, we identified a small amount of lower level of evidence that suggests that for some individuals, gait deficits may continue beyond return to activity. The review also highlighted the need for improving research methods used in future studies examining gait in concussed persons.

These findings have direct implications for clinical tests aimed at detecting gait disturbances in individuals who suffer a concussion. Specifically, that these tests should include an assessment of gait velocity and side-to-side sway in order to be sensitive to gait disturbances that commonly occur following sport-related concussions. In order to enhance the assessment of these parameters, complex physical tasks such a dual-task gait may be required.

2. Development of a New Post-Concussion Functional Balance Testing Battery

Along with the findings from the systematic review, and a review of other literature related to balance assessment in sport-related concussion and other health conditions we recognized that:

  • Sport-related concussion likely impacts several aspects of balance control including static balance, dynamic balance, reaction time, and attention.7-10
  • The ability to identify deficits among these aspects of balance depends on the complexity of tasks used to examine them. For instance, these deficits might be detectable for a longer period of time under dual-task testing as compared to single-task testing.8, 11, 12
  • There is a lack of research examining balance control in individuals that have sustained a sport-related concussion under sport-specific tasks.

Next, we have proposed our findings to clinical experts in treating balance deficits that may result from a sport-related concussion to discuss their relevance and utility for developing a new method for examining balance following sport-related concussion. Clinical experts have further supported our findings, and provided valuable feedback related to the content of the needed balance testing method.

Based on the above steps, we have proposed a new functional balance testing battery that allows examination across multiple aspects of balance control following a sport-related concussion under single-task, dual-task, and sport-specific task (see Figure 1).13 While most of the balance tasks in the proposed battery have been borrowed from current literature examining balance recovery in athletes with sport-related concussion, the utility of the dual-task Balance Error Scoring System and sport-specific task to detect balance impairments have not been tested previously in individuals following sport-related concussion.
 

Figure 1. The structure of the new post-concussion functional balance testing battery

 

 

3.    Examining the New Post-Concussion Functional Balance Testing Battery

This phase of our research aims to examine the repeatability (reliability) of the newly proposed functional balance testing battery as well as the balance recovery status, after return to play in adolescent athletes with sport-related concussion in comparison to non-concussed controls.

This study will involve 68 adolescent (i.e., 13 – 18 years of age) athletes active in recreational or competitive sport (34 athletes who have returned to play following sport-related concussion in the last 60 days and 34 non-concussed controls) who will undergo two 60 minute balance testing sessions. To be eligible to participate, potential participants must be active in recreational or competitive sport; and report no lower extremity injury that caused absence from recreational/sport activities for more than one week within the last three months prior to testing, inner ear or sinus infection over the week prior to testing, uncorrectable vision dysfunction, and/or history of cognitive deficits or attention deficit hyperactivity disorder. Eligibility criteria for controls will be the same as those for concussed participants with the additional inclusion criterion of not receiving a diagnosis of sport-related concussion within the last year.

We are recruiting participants between January to December 2018 from a variety of locations including a university-based sports medicine clinic, private physiotherapy clinics, and other community sports organizations in Edmonton, Alberta.

Expected results

The knowledge gained from this research is intended to provide a foundation for a comprehensive functional balance testing protocol for evaluating balance-control recovery status at return to play following sport-related concussion. At this stage, we expect that the proposed functional balance testing battery will show a good reliability. We also hypothesize that athletes with sport-related concussion will show more balance impairments as compared to non-concussed controls.

The importance of this study

Athletes with a sport-related concussion may be at risk of other injuries when they return to play. A recent study has shown a 60% greater risk of sustaining future injuries after return to play in athletes with a history of sport-related concussion as compared to non-concussed athletes.14 This was attributed to persisting balance problems that may be hard to detect with currently used balance assessment methods.14 We believe that the new functional balance testing battery will provide clinicians with a comprehensive and challenging clinical tool for evaluating balance-control recovery status at return to play following sport-related concussion. This is expected to assist with return to play decision making, and will ultimately contribute to an improvement in long-term player welfare.

Acknowledgment

Phase two of this research is funded by the Faculty of Rehabilitation Medicine – University of Alberta. Thaer Manaseer is a PhD candidate who is sponsored by the Hashemite University.

Thaer Manaseer (MSc, BScPT, ATC) is a PhD candidate at the Department of Physical Therapy at the University of Alberta in Edmonton, Canada. He is a physical therapist and a certified athletic trainer from the Kingdom of Jordan. He completed his bachelor degree in physical therapy in 2004 from the University of Jordan in Amman, Jordan. In 2013, he completed his master degree in athletic training from the University of Central Oklahoma in Oklahoma, USA. Thaer’s research primarily focuses on balance assessment following a sport-related concussion in youth.


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