THE DEVELOPMENT OF chronic ankle instability is a

Transcription

1 1418 ORIGINAL ARTICLE Effects of Taping and Exercise on Ankle Joint Movement in Subjects With Chronic Ankle Instability: A Preliminary Investigation Eamonn Delahunt, PhD, Jeremiah O Driscoll, BSc, Kieran Moran, PhD ABSTRACT. Delahunt E, O Driscoll J, Moran K. Effects of taping and exercise on ankle joint movement in subjects with chronic ankle instability: a preliminary investigation. Arch Phys Med Rehabil 2009;90: Objective: To examine the effects of ankle joint taping and exercise on ankle joint sagittal plane and rear-foot frontal plane movement in subjects with chronic ankle instability. Design: Laboratory-based, repeated-measures study. Setting: University biomechanics laboratory. Participants: Subjects with chronic ankle instability (N 11) as defined by the Cumberland Ankle Instability Tool. Interventions: Each participant performed 3 single-leg drop landings onto a forceplate under 3 different conditions. These conditions were: condition 1 (no tape), condition 2 (taped), and condition 3 (postexercise taped). Main Outcome Measures: Kinematic data were used to identify ankle joint sagittal plane and rear-foot frontal plane positions at 50ms before initial contact (IC) and at IC, under each of the conditions. Results: There was a significant effect on the angle of ankle joint plantar flexion, both at 50ms before IC (F 2, , P.001) and at IC (F 2, , P.001), as a result of the application of tape. Post hoc analysis revealed that condition 1 (no tape) resulted in significantly greater plantar flexion angle at 50ms before IC than condition 2 (taped) ( ; P.002) and condition 3 (postexercise taped) ( ; P.01). Similarly, condition 1 (no tape) resulted in significantly greater plantar flexion at IC than both condition 2 (taped) ( ; P.001) and condition 3 (postexercise taped) ( ; P.001). No significant differences were evident between condition 2 (taped) and condition 3 (postexercise taped) (P.05). Conclusions: These results indicate that taping acted to reduce the degree of plantar flexion at both 50ms before and at IC with the ground, and that these reductions were retained even after exercise. From the School of Physiotherapy and Performance Science, University College Dublin (Delahunt); Mount Carmel Hospital, Dublin, Republic of Ireland (O Driscoll); School of Health and Human Performance, Dublin City University (Moran), Dublin, Republic of Ireland. Supported by the Chartered Physiotherapists in Sports and Exercise Medicine clinical interest group of the Irish Society of Chartered Physiotherapists. Presented to the Association of Chartered Physiotherapists in Sports Medicine, November 13, 2008, Belfast, Northern Ireland; and the International Foot and Ankle Biomechanics Community, September 4, 2008, Bologna, Italy. No commercial party having a direct financial interest in the results of the research supporting this article has or will confer a benefit on the authors or on any organization with which the authors are associated. Reprint requests to Eamonn Delahunt, PhD, School of Physiotherapy and Performance Science, University College Dublin, Health Sciences Centre, Belfield, Dublin 4, Republic of Ireland, eamonn.delahunt@ucd.ie /09/ $36.00/0 doi: /j.apmr Key Word: Rehabilitation by the American Congress of Rehabilitation Medicine THE DEVELOPMENT OF chronic ankle instability is a common occurrence after an initial episode of ankle sprain. 1 It has been suggested that CAI is the result of the interaction between numerous neuromuscular factors that give rise to the development of mechanical instability, FI, or both, with CAI being used as a generic term to encompass the neuromuscular insufficiencies experienced by subjects with mechanical instability or FI. 1 One mechanism of ankle injury involves a forced plantar flexion and inversion of the ankle/foot complex. 2 Recent deliberation has suggested that inappropriate positioning of the ankle/foot complex before impact with the ground during walking or landing from a jump could leave the lateral ligament complex of the ankle joint in a potentially injurious position. 3 Direct evidence to support this hypothesis has recently been reported. 4-6 It has been shown that subjects with ankle instability have an increased inverted position of the rear foot during the period before contact with the ground when landing from a jump. 5 The authors hypothesized that this increased inverted position of the rear foot leaves the lateral ligament complex of the ankle joint in a vulnerable position, and any unexpected contact with the ground could produce a hyperinversion injury. Furthermore, a study by Wright et al 7 has indicated that an increased touchdown plantar flexed position of the ankle joint may increase the susceptibility of subjects with FI to recurrent ankle sprains. Ankle joint taping is a common prophylactic measure used by those involved in sports. It has been shown that the use of ankle joint taping can reduce the incidence of ankle sprains in physically active people. 8 Recent evidence suggests that ankle joint taping has proved to be more effective in reducing the incidence of recurrent rather than first-time ankle sprains. 9 It has been suggested that in contrast to the abundance of published works regarding the role of external ankle supports on various biomechanical parameters in noninjured subjects, little information is available on the effects of ankle joint taping on biomechanical parameters in subjects with CAI during functional activities, such as jump landing. 10 To our knowledge, to date, no study has investigated the effects of ankle joint taping, both before and after a bout of exercise, on rear-foot frontal plane and ankle joint sagittal plane movement during a functional drop landing in subjects with CAI. CAI CAIT FI IC List of Abbreviations chronic ankle instability Cumberland Ankle Instability Tool functional instability initial contact

2 TAPING IN SUBJECTS WITH ANKLE INSTABILITY, Delahunt 1419 The aims of this study were to examine the effects of ankle joint taping on ankle joint sagittal plane and rear-foot frontal plane movement in subjects with CAI while they performed a drop landing; and to determine the effects of exercise on the potential restrictive capabilities of taping. We hypothesized that ankle joint taping would restrict both ankle joint sagittal plane and rear-foot frontal plane movement, and that the tape would lose its restrictive capabilities after a bout of exercise. METHODS Subjects Eleven subjects (7 men, 4 women) with a history of unilateral CAI resulting from an episode of previous lateral ankle sprain volunteered to participate in the study. Ankle instability was defined as a score of 24 or less out of 30 on the CAIT. 11,12 Ankle sprain was defined as an inversion injury that required a period of protected weight bearing and/or immobilization. 5 Participants were excluded from the study if they had a history of fracture or surgery to the lower limb, if they were receiving formal rehabilitation for a previous episode of ankle inversion injury, or if they had any neurologic or vestibular impairments that could affect performance. The subjects were acquainted with the aim of the study, instructed about the experimental procedure, and asked to sign an informed consent form before participating in the study. The university ethical committee and research review board approved the study. Test Protocol Before performing the test, enough time was allowed for each subject to become familiar with the equipment, testing procedure, and drop landing technique. All subjects were allowed a maximum of 5 practice drop landings before testing. Subjects stood on a 30cm high platform in front of a forceplate with the test leg relaxed and bearing no weight. The subject used the contralateral leg to propel himself or herself from the platform; with subjects were required to balance as quickly as possible on the test leg in the center of the forceplate. A similar drop landing protocol has been previously described by Delahunt, 5 Caulfield, 13 and colleagues. During the testing procedure, no subject complained of any discomfort or pain while performing the drop landing test. The test sequence was as follows. Each subject performed 3 single-leg sagittal plane drop landings with no tape (condition 1, no tape). Tape was then applied to the test ankle joint by the principal investigator as described below. The subject then performed 3 single-leg sagittal plane drop landings with the ankle joint taped (condition 2, taped). The subject then performed all exercises outlined in the exercise protocol with the ankle joint taped. After completion of the exercise protocol, the subject then performed another 3 single-leg sagittal plane drop landings (condition 3, postexercise taped). Taping Procedure The application of tape was performed by the principal investigator in all instances. Each subject was positioned in a long sitting position on a treatment plinth. The feet were actively held in a dorsiflexed and everted position. Initially 2 anchor strips were applied, one approximately 5cm proximal to the malleoli and the second one at the level of the metatarsal heads. Foam prewrap (M Wrap) a was then applied in a figure of 8 around the ankle joint extending upward and downward to the anchor strips. Zinc oxide tape (1.5in; M Tape a ) was used for the rest of the procedure. A vertical stirrup was applied starting on the medial side of the proximal anchor, continuing down under the heel and up to the lateral side to attach to the proximal anchor with tension. A horizontal stirrup was then applied starting on the lateral side of the distal anchor, continuing across the lateral malleolus and behind the Achilles tendon and attaching to the medial side of the distal anchor with tension. The vertical and horizontal stirrups were then repeated twice more, with each stirrup overlapping the previous one by approximately one third. Two reinforcement heel locks were applied starting on the anteromedial side of the proximal anchor, angling the tape down and laterally, around the back of the Achilles tendon and under the heel up to the lateral side of the leg to the proximal anchor. Two lateral subtalar slings were then applied according to the method described by Wilkerson et al. 14 Finally, locking strips were applied to fill in between the anchor strips to hold all the other strips in place. Exercise Protocol The specific exercise protocol is outlined in table 1. Subjects first performed ten 60-cm forward hops, followed immediately by 10 lateral and 10 medial 60-cm hops. After this hopping sequence, subjects immediately progressed to the series of ladder drills. Each subject performed 10 repetitions of each drill. The only rest time allowed was the time required to walk back to the start of the ladder. Thus, subjects exercised almost continuously. After the completion of the ladder drills, the subjects then carried out the slalom and cutting drills. Again, each subject performed 10 repetitions of each drill; the only rest time allowed was the time it took to return to the starting point. The exercise protocol took on average 25 minutes to complete. Data Collection Twelve MX3 high-speed motion capture cameras b were used to provide information about the 3-dimensional segment angular displacements by tracking the position of retroreflective markers attached to specific anatomic landmarks on the subject s body. These landmarks were those outlined in the lower body plug-in model of the Vicon user s manual, b and as previously described by Kinsella and Moran. 15 The retroreflective markers were sampled at 250Hz. An AMTI forceplate c was used to capture kinetic data at 250Hz and was subsequently used for the identification of IC with the ground. Kinematic and kinetic data were synchronized and triggered by the principal investigator. Table 1: Exercise Protocol Activity Repetitions Hopping drills Anterior hop 60cm 10 Lateral hop 60cm 10 Medial hop 60cm 10 Ladder drills Lateral shuffle 10 Medial shuffle 10 Lateral hopping 10 Medial hopping 10 Single-leg slalom drill 10 Cutting drills Slalom drill around cones 10 Lateral spider (shuttle) drills 10

3 1420 TAPING IN SUBJECTS WITH ANKLE INSTABILITY, Delahunt The angle of rear-foot frontal plane (inversion/eversion) and ankle joint sagittal plane (plantar flexion/dorsiflexion) movement were measured at 50ms before and at IC with the ground. Three trials were completed for each testing condition, and the average was used to determine a representative value. Statistical Analysis The effect of taping, both before and after exercise, was assessed by a within-subjects 1-way analysis of variance. The 3 conditions were: condition 1 (no tape), condition 2 (taped), and condition 3 (postexercise taped). When a significant effect was evident, a Bonferroni adjusted pairwise comparison was undertaken. The level of significance was set at P less than.05. All analyses were completed by SPSS (version 15.0). d Calculation and interpretation of effect sizes for significant differences were determined by the methods described by Cohen. 16 RESULTS There was no significant effect on rear-foot frontal plane movement (inversion/eversion) movement, either at 50ms before (F 2,18 1.2, P.32) or at IC with the ground (F 2,18 0.4, P.68). However, there was a significant effect on the angle of ankle joint plantar flexion, both at 50ms before IC (F 2, , P.001) and at IC (F 2, , P.001). Post hoc analysis revealed that condition 1 (no tape) resulted in significantly greater plantar flexion at 50ms before IC than condition 2 (tape) ( ; P.002) and condition 3 (postexercise tape) ( ; P.01). Similarly, condition 1 resulted in significantly greater plantar flexion at IC than both condition 2 ( ; P.001) and condition 3 ( ; P.001). No significant differences were evident between condition 2 and condition 3 (P.05). Effect sizes for the differences between condition 1 and conditions 2 and 3 at 50ms before IC were 1.0 and 1.02, respectively, indicating a strong effect due to the application of tape. Effect sizes for the differences between condition 1 and conditions 2 and 3 at IC were.71 and.64, respectively, indicating a moderate effect due to the application of tape. These results indicate that taping acted to reduce the degree of plantar flexion at both 50ms before and at IC with the ground, and that these reductions were retained even after exercise. All results for the effect of taping and taping postexercise on ankle joint sagittal plane (plantar flexion/dorsiflexion) and rearfoot frontal plane (inversion/eversion) movement are summarized in table 2. Table 2: Effect of Taping and Taping With Exercise on Rear-Foot Frontal Plane (inversion/eversion) and Ankle Joint Sagittal Plane (plantar flexion/dorsiflexion) Movement 50ms Prior to, and at IC With the Ground Characteristics Condition 1 (no tape) Condition 2 (tape) Condition 3 (postexercise tape) Inversion at 50ms before IC ( ) Inversion at IC ( ) Plantar flexion at 50ms before IC ( ) * * Plantar flexion IC ( ) * * NOTE. Values are mean SD. Negative values for inversion represent an everted position. *Significantly less than condition 1 (no tape). DISCUSSION Our principal findings were that ankle joint taping reduced the degree of ankle joint plantar flexion both immediately before and at IC with the ground during a functional drop landing technique in subjects with CAI. Furthermore, the restrictions imposed by the taping technique were maintained after a 25-minute exercise protocol replicating sporting activities. A recent muscle model driven computer simulation has shown that an increased plantar flexed position of the foot/ ankle complex may cause an increase in the susceptibility of subjects with a history of ankle sprains to repeated injury to the lateral ligament complex of the ankle joint. 7 The results of this study indicated that the more plantar flexed the foot/ankle complex was at IC with the ground, the greater the incidence of excessively induced supination. Thus, the authors concluded that the susceptibility to ankle sprains and in particular damage to the anterior talofibular ligament is increased by an increase in ankle joint plantar flexion position at IC with the ground. Thus, ankle joint taping may function to influence the sagittal plane movement of the foot/ankle complex. 7 The results of the present study indicate that this is the case. During the drop landing protocol, the application of tape restricted the degree of ankle joint plantar flexion movement both before and at IC with the ground. Recent evidence has shown that ankle joint taping and bracing can reduce the incidence of subsequent ankle sprains. 8 Furthermore, in a numbers-need-totreat study, Olmsted et al 9 indicated that ankle joint taping and bracing are better in subjects with a history of FI compared with subjects with no history of ankle joint injury. Thus, we believe that the findings of the present study are important and support the previously reported hypothesis that ankle joint taping provides a restrictive effect on ankle joint plantar flexion movement in subjects with a history of ankle joint injury. 7 An interesting finding was that there was no difference between condition 2 (taped) and condition 3 (postexercise taped). Previous research has suggested that the restriction imposed by ankle joint tape can be significantly reduced in as little as 10 minutes of exercise. 17 However, the present study differs from previous research: to our knowledge, no study has investigated the effect of ankle joint taping and exercise on ankle joint movement during a functional task. Furthermore, the findings of this study are new and important because they specifically relate to subjects with CAI, whereas previous research has tended to use uninjured subjects. The exercise protocol we used consisted of a series of hopping, ladder, and cutting drills. These exercises were specifically chosen to replicate functional sporting activities, and many of these drills are used as training drills for various field and court sports. After the exercise protocol, subjects were immediately tested by single-leg sagittal plane drop jumps, with no differences in plantar flexion ankle joint movement being observed before and after exercise. Thus, these results suggest that the taping technique used was resilient to the stresses and strains of the imposed exercise protocol. The results of the present study agree with the findings of a meta-analysis conducted by Cordova et al, 18 who concluded that ankle joint taping is an effective method of restricting ankle joint plantar flexion range of movement and that this particular restrictive capability of ankle joint tape is not lost after a period of exercise. However, the exercise protocol in the present study took on average 25 minutes to complete, which does not replicate the duration of any field or court sport. Thus, extrapolation of these results to competitive situations warrants careful consideration.

4 TAPING IN SUBJECTS WITH ANKLE INSTABILITY, Delahunt 1421 One of our original hypotheses was that ankle joint taping would restrict rear-foot frontal plane movement. Previous research has shown that subjects with ankle instability exhibit an increased inverted position of the rear foot during jump landing. 5 The authors of this previous study indicated that subjects with ankle instability had an increased time-averaged inverted position of the ankle joint from the time period 200ms pre-ic to 95ms pre-ic. Direct comparison with this study was not possible because we only measured ankle joint frontal plane movement at 50ms pre-ic and at IC. Thus, the addition of a lateral subtalar sling to the taping technique may not have had any functional significance during a drop landing technique. The main function of the subtalar sling is to restrict subtalar joint inversion. 19 Thus, if subjects with ankle instability do not exhibit an increased inversion position of the rear foot immediately before and at IC with the ground during a jump landing, then the subtalar sling may offer no specific benefit during this type of activity. Thus, the jump landing protocol used may not have been sufficiently sensitive to detect differences that the lateral subtalar sling may offer. Perhaps a more specific application of the lateral subtalar sling would be for running and walking. During the terminal swing phase of the gait cycle, the lateral border of the foot comes in close approximation with the ground, and Konradsen and Voigt 20 have presented a biomechanical model that suggests that an increased inverted position of the foot/ankle complex during the terminal swing phase of the gait cycle can predispose subjects with FI to an increased incidence of experiencing a sprain. Further evidence to support the biomechanical model put forward by Konradsen and Voigt 20 has recently been published. 4,6 The lateral subtalar sling may offer greater clinical and functional significance during running and walking than during jump landing. Furthermore, the functional significance of an increased inverted position of the rear foot before contact with the ground during a jump landing requires consideration. As indicated by Wright et al, 7 it seems that an increased plantar flexed position of the ankle joint at the point of IC with the ground is the most significant consideration and correlates with an increased susceptibility to repeated ankle sprain. Study Limitations The present study does have a number of limitations that require consideration when interpreting the results. First, the small sample size leads us to recommend that future studies recruit a larger number of subjects. Considering that the present study was a preliminary investigation, we are encouraged by the observed restrictions in ankle joint sagittal plane kinematics, and we thus recommend that a similar study with a larger sample size, as well as the addition of a control group with no history of ankle joint injury, be undertaken. However, a strength of this study was that we used a valid and reliable tool in the CAIT as the method of including subjects. Thus, the present study does include a homogenous group of subjects with CAI, as identified by use of the CAIT. The lack of a homogenous group has previously received attention in the literature, with concerns regarding the lack of a universally agreed-on definition for CAI as well as the lack of specific inclusion criteria. 21 Thus, it is necessary that future studies use valid and reliable tools to measure the severity of CAI. For the application of the tape, it was necessary to remove 3 lower-limb markers. The markers that were removed were those placed on the head of the second metatarsal, the lateral malleolus, and the posterior aspect of the calcaneus. A limitation of the present study was that we did not test the reliability of our marker placements. However, the same examiner was responsible for marker applications. Furthermore, even with the tape on, the head of the second metatarsal is easily identified, and so too is the marker position on the posterior aspect of the calcaneus because this marker is placed at the same height as the marker placed on the head of the second metatarsal. To ensure correct placement of the marker on the lateral malleolus, the height of the initial placement was measured from the ground in millimeters, as well as the perpendicular distance from the posterior aspect of the Achilles tendon in millimeters. Thus, we believe that these measurements would have reduced the problems with incorrect marker placement after the removal of markers and subsequent application of the tape. A final limitation of the present study concerns the applicability of the drop landing protocol to the field situation, and the mechanism of ankle joint injury. We chose to use this drop landing protocol because it has previously been used by Caulfield and Garrett, 13 as well as Delahunt et al. 5 However, this drop landing protocol may not sufficiently challenge the ankle joint stability mechanisms required for dynamic joint stabilization during sports participation. Thus, we would recommend that future studies use a combination of different drop and jump landing protocols. CONCLUSIONS The results of the present study have shown that ankle joint taping can restrict sagittal plane movement at the ankle joint during drop landing activities in subjects with CAI. Furthermore the restrictive capabilities of the taping technique are maintained after 25 minutes of exercise. References 1. Hertel J. Functional anatomy, pathomechanics, and pathophysiology of lateral ankle instability. J Athl Train 2002;37: Garrick JG. The frequency of injury, mechanism of injury, and epidemiology of ankle sprains. Am J Sports Med 1977;5: Tropp H. Commentary: functional ankle instability revisited. J Athl Train 2002;37: Delahunt E, Monaghan K, Caulfield B. Altered neuromuscular control and ankle joint kinematics during walking in subjects with functional instability of the ankle joint. Am J Sports Med 2006; 34: Delahunt E, Monaghan K, Caulfield B. Changes in lower limb kinematics, kinetics and muscle activity in subjects with functional instability of the ankle joint during a single leg drop jump. J Orthop Res 2006;24: Monaghan K, Delahunt E, Caulfield B. Ankle function during gait in patients with chronic ankle instability compared to controls. Clin Biomech 2006;21: Wright IC, Neptune RR, van den Bogert AJ, Nigg BM. The influence of foot position on ankle sprains. J Biomech 2002;33: Mickel TJ, Bottoni CR, Tsuji G, Chang K, Baum L, Tokushige KA. Prophylactic bracing versus taping for the prevention of ankle sprains in high school athletes: a prospective, randomized trial. J Foot Ankle Surg 2006;45: Olmsted LC, Vela LI, Denegar CR, Hertel J. Prophylactic ankle taping and bracing: a numbers-needed-to-treat and cost-benefit analysis. J Athl Train 2004;39: Cordova ML, Ingersoll CD, Palmieri RM. Efficacy of prophylactic ankle support: an experimental perspective. J Athl Train 2002; 37: Hiller CE, Refshauge KM, Bundy AC, Herbert RD, Kilbreath SL. The Cumberland ankle instability tool: a report of validity and reliability testing. Arch Phys Med Rehabil 2006;87:

5 1422 TAPING IN SUBJECTS WITH ANKLE INSTABILITY, Delahunt 12. Sawkins K, Refshauge K, Kilbreath S, Raymond J. The placebo effect of ankle taping in ankle instability. Med Sci Sports Exerc 2007;39: Caulfield B, Garrett M. Changes in ground reaction force during jump landing in subjects with functional instability of the ankle joint. Clin Biomech 2002;19: Wilkerson GB, Kovaleski JE, Meyer M, Stawiz C. Effects of subtalar sling ankle taping technique on combined talocruralsubtalar joint motions. Foot Ankle Int 2005;26: Kinsella S, Moran K. Gait pattern categorization of stroke participants with equinus deformity of the foot. Gait Posture 2008;27: Cohen J. Statistical power analysis for the behavioural sciences. 2nd ed. Hillsdale: Lawrence Erlbaum; Manfroy PP, Ashton-Miller JA, Wojtys EM. The effect of exercise, pre-wrap, and athletic tape on the maximal active and passive ankle resistance of ankle inversion. Am J Sports Med 1997;25: Cordova ML, Ingersoll CD, LeBlanc MJ. Influence of ankle support on joint range of motion before and after exercise: a meta-analysis. J Orthop Sports Phys Ther 2000;30: Wilkerson GB. Biomechanical and neuromuscular effects of ankle taping and bracing. J Athl Train 2002;37: Konradsen L, Voigt M. Inversion injury biomechanics in functional ankle instability: a cadaver study of simulated gait. Scand J Med Sci Sports 2002;12: Konradsen L. Sensori-motor control of the uninjured and injured human ankle. J Electromyogr Kinesiol 2002;12: Suppliers a. Mueller Sports Medicine Inc, PO Box 99, Prairie du Sac, WI b. Vicon Oxford Metrics, 14 Minns Business Park West Way, Oxford, UK OX2-OJB. c. AMTI, 176 Waltham St, Watertown, MA d. SPSS, 233 S Wacker Dr, 11th Fl, Chicago, IL