The purpose of this study was to determine if there were any differences in ankle range of motion, strength, or work between persons with normal ankles (Normal, n = 14), those with functional ankle instability (FAI, n = 15), and those with a history of FAI who have been through formal proprioceptive rehabilitation (Rehab, n = 14). A second puipose was to determine normative values for ankle strength and work measurements using the Biodex® isokinetic system. There were no significant differences between groups for ankle range of motion or for any strength or work measurements. The overall strength/work averages were 11.75/3.42 for plantar flexion, 339/1.48 for dorsiflexion, 3.30/2.40 for inversion, and 2.62/1.79 for eversion. Dorsiflexion torque overall was 31.43% of plantar flexion, and the evertors produced 75.42% of the torque produced by the invertors. It is recommended that clinicians continue to rehabilitate ankles with strength and proprioceptive exercises but do not rely on ankle strength/work testing as the only criteria for determining an athlete's readiness to return to full activity.
Cynthia M. McKnight and Charles W. Armstrong
Cathleen Brown, Scott Ross, Rick Mynark and Kevin Guskiewicz
Functional ankle instability (FAI) is difficult to identify and quantify.
To compare joint position sense (JPS), time to stabilization (TTS), and electromy-ography (EMG) of ankle musculature in recreational athletes with and without FAI.
Case-control compared with t tests and ANOVAs.
Sports medicine research laboratory.
20 recreational athletes.
Main Outcome Measures:
Passive angle reproduction, TTS, and mean EMG amplitude of the tibialis anterior, peroneals, lateral gastrocnemius, and soleus muscles during single-leg-jump landing.
No differences in JPS or medial-lateral TTS measures between groups. Significantly longer anterior-posterior TTS (P < .05) in the unstable ankle group. The stable ankle group had significantly higher mean EMG soleus amplitude after landing (P < .05). No other significant differences were found for mean EMG amplitudes before or after landing.
Subjects with FAI demonstrated deficits in landing stability and soleus muscle activity during landing that may represent chronic adaptive changes following injury.
Cynthia J. Wright and Brent L. Arnold
Force sense (FS), the proprioceptive ability to detect muscle-force generation, has been shown to be impaired in individuals with functional ankle instability (FAI). Fatigue can also impair FS in healthy individuals, but it is unknown how fatigue affects FS in individuals with FAI.
To assess the effect of fatigue on ankle-eversion force-sense error in individuals with and without FAI. Design: Case control with repeated measures.
Sports medicine research laboratory.
32 individuals with FAI and 32 individuals with no ankle sprains or instability in their lifetime. FAI subjects had a history of ≥1 lateral ankle sprain and giving-way ≥1 episode per month.
Three eversion FS trials were captured per load (10% and 30% of maximal voluntary isometric contraction) using a load cell before and after a concentric eversion fatigue protocol.
Main Outcome Measures:
Trial error was the difference between the target and reproduction forces. Constant error (CE), absolute error (AE), and variable error (VE) were calculated from 3 trial errors. A Group × Fatigue × Load repeated-measures ANOVA was performed for each error.
There were no significant 3-way interactions or 2-way interactions involving group (all P > .05). CE and AE had a significant 2-way interaction between load and fatigue (CE: F 1,62 = 8.704, P = .004; AE: F 1,62 = 4.024, P = .049), and VE had a significant main effect for fatigue (F 1,62 = 5.130, P = .027), all of which indicated increased FS error with fatigue at 10% load. However, at 30% load only VE increased with fatigue. The FAI group had greater error as measured by AE (F 1,62 = 4.571, P = .036) but not CE or VE (P > .05).
Greater AE indicates that FAI individuals are less accurate in their force production. Fatigue impaired force sense in all subjects equally. These deficits provide evidence of impaired proprioception with fatigue and in individuals with FAI.
Michael E. Powers, Bernadette D. Buckley, Thomas W. Kaminski, Tricia J. Hubbard and Cindy Ortiz
The combined effects of strength and proprioception training, especially in individuals with ankle instability, have not been studied extensively.
To examine the influence of 6 weeks of strength and proprioception training on measures of muscle fatigue and static balance in those with unilateral functional ankle instability (FAI).
Pretest–posttest, randomized groups.
A climate-controlled sports-medicine research laboratory.
38 subjects with self-reported unilateral FAI.
Muscle fatigue was determined using the median power frequency (f med) from an electromyographic signal, and static balance was assessed using center-of-pressure values obtained from a triaxial force plate.
There were no significant effects of the strength or proprioception training on our measures of muscle fatigue and static balance.
Strength training, proprioception training, and the combination of the 2 failed to improve postural-stability characteristics in a group of subjects with FAI.
Diane Madras and J. Bradley Barr
The article presents a focused review of the literature surrounding training methods for addressing the proprioceptive loss and subsequent balance problems that result from inversion ankle sprains.
The authors searched the MEDLINE and CINAHL databases for the period 1985 through December 2001 using the key words ankle, ankle sprain, and rehabilitation.
Any study investigating a rehabilitation or prevention program for the proprioceptive or balance aspects of ankle instability was included.
Key components of the training regimen used in each study are described, and major findings are summarized.
Based on the literature reviewed, there is evidence to suggest that training programs for individuals with ankle instability that include ankle-disk or wobble-board activities help improve single-leg-stance balance and might decrease the likelihood of future sprains.
Jennifer F. Mullins, Arthur J. Nitz and Matthew C. Hoch
in individuals with CAI? Search Strategy A computerized search was completed in March 2018 (Figure 1 ). The search terms used to guide the search strategy were: • P atient Group: ankle instability, chronic ankle instability, functional ankle instability • I ntervention: Dry need*, intramuscular
Bethany Wisthoff, Shannon Matheny, Aaron Struminger, Geoffrey Gustavsen, Joseph Glutting, Charles Swanik and Thomas W. Kaminski
the MAI group are reported in Table 3 . Table 1 Average Sagittal Plane Peak Torque (N·m) Strength Measures Plantar flexion Dorsiflexion Concentric Eccentric Concentric Eccentric 30 m/s 120 m/s 30 m/s 120 m/s 30 m/s 120 m/s 30 m/s 120 m/s Functional ankle instability Without 164.4 (57.6) 102.7 (47
Alan R. Needle, Thomas W. Kaminski, Jochen Baumeister, Jill S. Higginson, William B. Farquhar and C. Buz Swanik
Rolling sensations at the ankle are common after injury and represent failure in neural regulation of joint stiffness. However, deficits after ankle injury are variable and strategies for optimizing stiffness may differ across patients.
To determine if ankle stiffness and muscle activation differ between patients with varying history of ankle injury.
Fifty-nine individuals were stratified into healthy (CON, n = 20), functionally unstable (UNS, n = 19), and coper (COP, n = 20) groups.
Main Outcome Measures:
A 20° supination perturbation was applied to the ankle as position and torque were synchronized with activity of tibialis anterior, peroneus longus, and soleus. Subjects were tested with muscles relaxed, while maintaining 30% muscle activation, and while directed to react and resist the perturbation.
No group differences existed for joint stiffness (F = 0.07, P = .993); however, the UNS group had higher soleus and less tibialis anterior activation than the CON group during passive trials (P < .05). In addition, greater early tibialis anterior activation generally predicted higher stiffness in the CON group (P ≤ .03), but greater soleus activity improved stiffness in the UNS group (P = .03).
Although previous injury does not affect the ability to stiffen the joint under laboratory conditions, strategies appear to differ. Generally, the COP has decreased muscle activation, whereas the UNS uses greater plantar-flexor activity. The results of this study suggest that clinicians should emphasize correct preparatory muscle activation to improve joint stiffness in injury-rehabilitation efforts.
Jupil Ko, Erik Wikstrom, Yumeng Li, Michelle Weber and Cathleen N. Brown
International Ankle Consortium 1 inclusion criteria was used (1) reporting ≤25 on the Cumberland Ankle Instability Tool (CAIT) 16 , 17 and ≥11 on the Identification of Functional Ankle Instability (IdFAI), 18 (2) a history of at least one significant (moderate–severe) ankle sprain which caused an
Abbis H. Jaffri, Thomas M. Newman, Brent I. Smith, Giampietro L. Vairo, Craig R. Denegar, William E. Buckley and Sayers J. Miller
giving away and/or recurrent sprains 6 months before participation in the study, and (3) a score >11 on the Identification of Functional Ankle Instability. Only participants who presented with unilateral CAI were selected for this study group. Procedures This study was approved by the institutional