Original Citation: Terada, M., Kosik, K. B., McCann, R. S., & Gribble, P. A. (2016). Diaphragm Contractilityin Individuals with Chronic Ankle Instability. Medicine and science in sports and exercise.

Why is this relevant?:

The rehabilitation for an ankle sprain has consisted of stretching and strengthening exercises for the foot/ankle complex, as well as balance activities. the ankle remains a clear area of the body that is very vulnerable to re-injury . Authors investigated the effect of distal injuries on proximalsegments of the body.  The research study reviewed in this article compares the function of the diaphragm in individuals with and without chronic ankle instability.

Chronic Ankle Instability –

Study Summary
Study Design : Single Blinded Case Control Design
Level of Evidence III - Evidence from non-experimental descriptive studies, such as compa

Demographics data:

Volunteers were recruited from a local college campus and divided into a control group (CONG) with 28 participants and chronic ankle instability group (CAIG) with 27 participants.
* Age: CAIG = 22.58 yrs

CONG = 21.04 yrs

* Gender: CAIG = 4 male/23 female;

CONG = 9 male/19 female

* Inclusion Criteria:

  • for the CAIG: h/o of at least 1 significant lateral ankle sprain
  • reports of ankle “giving way” at least twice in past 6 months;
  • ongoing ankle instability & dysfunction during daily activities;
  • score of >5 on the Ankle Instability Instrument
  • score of >11 on the Identification of Functional Ankle Instability
  • <24 on the Cumberland Ankle Instability Tool .
  •  for the CONG: no history of lateral ankle sprain; score of 0 on Ankle Instability Instrument  & Functional Ankle Instability, score of 30 on Cumberland Ankle Instability Tool

* Exclusion Criteria:

  • Diagnosed balance or vestibular disorders, self reported low back pain,
  • surgery in the lower extremity, concussion in the past 6 months,
  • diagnosed cardiopulmonary disorder, scoliosis,
  • Ankylosing spondylitis or any other condition that can affect respiratory system,
  •  Self reported nusculoskeletal and neuromuscular injuries > 2yrs(other than lateral ankle sprain)

Outcome Measures:

Participant Characteristics:
* Physical Activity Levels  (GLTEQ)
* Height
* Body Mass

Diaphragm Contractility:

* Right and Left hemi diaphragm thickness was measured at the end of resting inspiration & expiration  in supine postition. For statistical analysis. Greater change in thickness from inspiration to expiration indicated greater contractility.

Results :

* Height, Body Mass, BMI and physical activity levels were not significantly different between the groups (p>.05).
* CAIG scored significantly higher on the Ankle Instability Instrument  & Identification of Functional Ankle Instability  measures (p<.001).
* CAIG scored significantly lower on the Cumberland Ankle Instability Tool (p<.001).
* CAIG had a lesser degree of left hemi diaphragm contractility compared to CONG (p=.03).
* There was not a significant difference in contractility between the groups for the right hemi diaphragm, although the CAIG demonstrated a trend toward decreased contractility (p=.31).


This study demonstrated that there is an altered neuromuscular strategies are observable proximal to the lower leg in individuals with chronic ankle instability.  There is an altered left hemi-diaphragm function observed in individuals with chronic ankle instability . This may indicate impairments in more proximal segments systems.

From the Researchers point of view :

The researchers find out  that who has left hemi diaphragm smaller degree of contractility  when compared to uninjured controls. It is possible this difference in diaphragm function observed between the groups. It may indicate that there is an altered strategies of neuromuscular function from the CNS (central nervous system)

Why is this study important?

It may be necessary to address diaphragm function and trunk stability in individuals with a history of ankle sprains. In addition to that , this study may provide the evidence of future ankle sprain issues that can be from an inhibited Intrensic subsystem and poor trunk control (such as low back pain).

How does it help your clinical  practice?

It indicates the clinical implication at multiple levels. It supports the trunk stabilization activities for individuals recovering from an ankle sprain. .

Second, it may be important to stress breathing during exercise programme . Therefore the diaphragm is challenged to function simultaneously for respiration and core stabilization.

Finally , this study serves the purpose of  thorough in our subjective assessment – Whether working with acutely & chronic injury, or uninjured individuals , it is an advantage  to understand how prior injures may contribute to developing compensations pattern which leads to future injury. For example, a history of ankle sprain five years ago, enters your office/gym/clinic and is currently complaining of low back pain.  When your ankle hurts , your low back will receive a compensation pattern in future.

Intrinsic  subsystem should fire prior to movement of the extremities. During neuromuscular re-education the diaphragm, TVA, multifidus and pelvic floor are designed to fire together,Unless there is significant structural dysfunction.

Here are link of an exercise that we conclude from the study . Implement the exs for future prevention of injury.

Take note :

1. Always check distal segment of an injury part

2. Integrated approach of an exercise is benefits for prevention of injury .

3. Impaired trunk and postural stability in individuals with chronic ankle instability . The diaphragm muscle contributes to trunk and postural stability by modulating the intra-abdominal pressure. A potential mechanism that could help to explain trunk and postural stability deficits. When supraspinal sensorimotor changes diaphram function may be altered with Chronic ankle instability

Referance for exercises :

    1. Hodges, P. W., Butler, J. E., McKenzie, D. K., & Gandevia, S. C. (1997). Contraction of the human diaphragm during rapid postural adjustments. The Journal of physiology, 505(Pt 2), 539-548
    2. O’Sullivan, P. B., Beales, D. J., Beetham, J. A., Cripps, J., Graf, F., Lin, I. B., … & Avery, A. (2002). Altered motor control strategies in subjects with sacroiliac joint pain during the active straight-leg-raise test. Spine, 27(1), E1-E8.
    3. Swenson, D. M., Yard, E. E., Fields, S. K., & Comstock, R. D. (2009). Patterns of recurrent injuries among US high school athletes, 2005–2008.The American journal of sports medicine, 37(8), 1586-1593.
    4. Kolar, P., Sulc, J., Kyncl, M., Sanda, J., Neuwirth, J., Bokarius, A. V., Kriz, J. & Kobesova, A. (2010). Stabilizing function of the diaphragm: dynamic MRI and synchronized spirometric assessment. Journal of Applied Physiology, 109(4), 1064-1071.
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