Wobble Board Training After Partial Sprains of the Lateral Ligaments of the Ankle: A - Prospective Randomized Studv

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1 Wobble Board Training After Partial Sprains of the Lateral Ligaments of the Ankle: A - Prospective Randomized Studv lens Ulrik Wester, MD ' Stig Mindedahl jespersen, MD * Keld Daubjerg Nielsen, MD lars Neumann, M D ~ A t the casualty department.. in Scandinavia, 7-10% of the injuries are ankle sprains. This injury is the most common injury in sports (13,20). Eightyfive percent of the sprains involve plantar flexion and supination. In 65% of the sprains, the injury is located only in the anterior talofibular ligament. With more violent inversion force, 20% also suffer damage to the calcaneofibular ligament. The calcaneofibular and the posterior talofibular ligaments are seldom rup tured alone (14). Traditional sprains of the ankle have been classified into three grades. Grade 1 injury (mild) involves stretching of the ligament without macroscopic tearing, mild swelling, or tenderness, and no mechanical instability of the joint. Grade 2 injury (moderate) involves a macroscopic tear of the ligament with moderate pain, swelling, and tenderness, but no instability of the joint. Grade 3 injury (severe) involves a complete rupture of the ligaments with severe swelling and tenderness (6,10,13). The joint is unstable. Clinical testing following ankle sprains, including anterior drawer test and talar tilt test, should always be done. Positive findings of these tests indicate a stage 3 injury. If the Ankle sprains are often complicated by functional instability and repeated ankle sprains. Rehabilitation with wobble boards in patients with functional instability has been tested, and significant improvement has been found compared to no training. The aim of this study was to investigate whether the number of patients with residual symptoms following ankle sprains could be reduced by training on a wobble board during a 12-week recovery period. In addition, the influence of training in the time course reduction of edema was investigated. We performed a prospective study including 61 patients, all active in sports for more than 2 hours a week with primary ankle sprains. The effect of a 12-week training program with wobble board was compared with no training. Fortysight patients completed the study. In the follow-up period (X = 230 days), we found significantly fewer recurrent sprains, and significantly fewer patients in the training group had functional instability of the ankle compared with the no training group. There were no differences in the two groups in the time which elapsed before patients were painless at walking, during running, or at sports. Volumetric measurements revealed no difference in the speed of reduction of hematoma and edema of the ankle and foot between the two groups. We conclude that training on a wobble board early after primary stage 2 ankle sprains is effective in reducing residual symptoms following this lesion and that training does not seem to affect the time course reduction in edema. Key Words: ankle sprain, functional instability, exercise training ' Department of Orthopaedics, Arhos University Hospital, Arhus, Denmark. Address for correspondence: Carl Baggers All4 43, 5250 Odense SV, Denmark. ' Department of Orthopaedics, Odense University Hospital, Odense, Denmark ' Department of Orthopaedics, Middelfart Hospital, Denmark Department of Orthopaedics, Odense University Hospital, Odense, Denmark Su~ported by a nrant from the Danish Society of Sports Medicine. clinical examination indicates a stage 1 or stage 2 injury, no further radiological examination is indicated. If clinical examination indicates a stage 3 injury, arthrography should be done within the first 24 hours of the trauma before fibrin clots seal ligaments and capsular tears. If the examination is done more than 24 hours after the trauma, stress radiographs should be done (14,19). If these radiological examinations indicate a stage 3 injury, early operation should be considered (19). The most common complications following ankle sprains are mechanical instability and functional instability. Mechanical instability is abnormally increased mobility and indicates a lesion of the passive stabilizers of the ankle, primarily the ligaments. Functional instability describes a situation in which the ankle is giving way and has a tendency of recurrent an- Volume 23 * Number 5 - May 1%6 * JOSPT

2 RESEARCH STUDY Patients were told to discontinue wobble board trail ning if painful. From weeks 1-3, sessions A-C are completed once daily; from weeks 4-6, sessions D-F are completed once daily. A. Stand with feet parallel on the board. Move the front edge against the floor. Then, move the board back, with the rear edge nearly touching the floor. During the exercise, the board should not touch the floor. ( Iontinue the movement for 15 seconds. Rest for 10 seconds. Repeat this session 10 times. B. Stand with feet parallel on the board and move I Ihe left edge against the floor. Then, move the right edge against the floor, with the board nearly touching the floor. Continue the movement for 15 seconds. R est for 10 seconds. Repeat this session 10 times. :A- ---a C. Stand with feet oarallel on the board. with feet -- :Ll L- L A-- -1.L- L---J f J..La L--d.-.L- -:-La.L-- *-.L- 1-r. as WIW dud11 ds wss~u~t.. IWUV~. 111t. IIUIN mrt. UI III~. wdr~ lurwdru; rrluvt. 111t. wdru IU ~ t rlrrlt.. werl IU III~. lelr. \,. Continue this ckculating movement for 60 seconds. Rest ior 20 konds. Repeat this session"five times. D. Stand with feet parallel and the knees flexed. Complete sessions A-C with flexed knees and hands on the back. Do movements in sessions A-C for 30 seconds. Rest for 20 seconds. Repeat this session five times. E. Stand with one foot on the board. Keep the board horizontal for 7 seconds. Repeat this session five times. F. Position is the same as in session E, but with eyes closed for the last 4 seconds. Repeat this session five times. TABLE 1. Training program during the 12-week recovery period. kle sprains (9.1 3,l9,2O). Functional instability is the most common residual symptom following ankle sprains and seems to occur in 17 to 58 percent of the patients (20). This lesion seems to be most common in younger patients (3). Many causes have been proposed: peroneal weakness, mechanical instability, and proprioceptor damage (8,9,20). Rehabilitation with wobble boards in patient5 with functional instability has been tested and found to produce significant improvement compared with no training (20). To continue examining this finding, we investigated whether the number of patient5 with residual symptoms after primary tears could be reduced by training on a wobble board. METHODS Subjects Fortyeight patients [19 women and 29 men with a mean age of 25 (+7.2)] with primary ankle sprains (stage 2) completed the study. All patients had tenderness and swelling located on the lateral side of the ankle. Furthermore, all patients had tenderness to palpation localized on the lateral side of the ankle, and all were active in sports for at least 2 hours a week. Patients with previous fractures in the ankle joint and patients with clinically demonstrable ankle instability (positive anterior drawer test or talar tilt test) were excluded. The patient5 were primarily examined at the local casualty department, and a plain radiograph of the ankle was made to exclude fractures (anteroposterior, lateral, and mortise views). All 48 patients received treatment at the casualty department, including a compression bandage for 1 week and leg elevation and immobilization for 2 days. The patients were told to avoid activities straining the Functional instability is the most common residual symptom following ankle sprains and seems to occur in 17 to 58 percent of the patients. lateral ligaments of the ankle, and resumption of sport.. activities was not permitted until daily activities were possible without any pain. Procedure The participants were divided into the training group or the no training group by drawing of envelopes. In addition to the treatment mentioned above, the patients in the training group were supplied with a.wobble board (wobble board diameter = 350 mm, ball radius = 75 mm, ball height = 50 mm) and commenced a 12-week training program involving training for 15 minutes a day according to a written program (Table 1). Participants in the no training group were given the usual treatment at the casualty department. All patients were reexamined 4-7 days later by an experienced orthopaedic surgeon (including anterior drawer test and talar tilt test). Further volumetric measurements and follow-up took place after 6 and 12 weeks. A final follow-up interview was performed 230 days (+62.9) after the ankle sprain. The study was approved by the local ethics committee and informed consent was obtained from each subject prior to data collection. Volumetric Measurements During examinations of the patients, the difference in volume of the injured and the uninjured ankle/ foot was registered using a newly developed water tank with an external tap (Figure 1). Before each measurement, the water level in the water tank was calibrated using the follow- FIGURE 1. Water tank used for the volumetric measurements. JOSPT Volume 23 Number 5 Mav 1996

3 ing procedure. The tap, which was placed outside on the bottom of the water tank, was turned off. Then the water tank was filled with soapy water to diminish the influence of the surface tension on our measurements. When all movement in the water tank had ceased, the tap was opened and the water ran out until it reached the level of the pipe. Then the tap was closed again, and the patient placed one foot at the bottom of the water tank with the heel against the back wall, ensuring equal positioning each time (Figure 1). When all movement in the water tank had ceased, the examiner opened the tap and the displaced water was collected in a bowl. The overflow was weighed. The difference between the injured and uninjured foot was considered to be an indication of the size of hematoma and edema. The reliability of measurement of the volumeter was determined to be 2 15 ml on an average of 20 trials on one uninjured subject. This corresponded to 1.2% of the volume of the foot/ankle. Questions at the Examinations At the examinations after 1, 6, and 12 weeks, the patients were questioned about pain at rest, during walking, or during sports activities (yes/no). An interview was performed after 230 (262.9) days, and the patients were asked about repeated ankle sprains, subjective feeling of giving way, whether they were still using tape or an ankle brace, and whether the injury had caused the patients to change their sports habits. Statistical Methods The Fischer test was used to test the difference between the number of patients with recurrent sprains in the training group compared to the number of patients with recurrent sprains in the no training group. The Fischer test was also used to test the difference in the number of patients with functional instability (subjective feeling of the ankle giving way) in the two groups. The differences in the volumetric measurements at 1, 6, and 12 weeks were compared in the training and no training group using the Kruskal-Wallis test. The alpha level was set at 0.05 for all analyses. RESULTS Fortyeight patients completed the study. Thirteen patients withdrew before final follow-up. The reasons given were: eight patients did not want to complete the study; two moved and could not be reached; one had a fracture of the ankle during the follow-up period; one had to stop ankle board training because of pain; and one patient began wobble board training in spite of being in the no training group. The mean Wobble board training was effective in reducing the number of recurrent distortions follow-up period was 230 days (262.9)- At the time of the ankle sprain, 22 of the patients were playing soccer, 11 were playing handball, five were playing volleyball, and 10 were participating in other sports. Twenty-six of the sprains were located in the right ankle. Of these, 23 patients were right-foot dominant. Twenty-two sprains were located in the left ankle. Of these, eight patients were left-foot dominant. Of the 24 patients in Group 1 (training group), six (25%) patients had recurrent sprains during the follow-up period and none had subjective instability of the ankle joint after completing the rehabilitation program. In Group 2 (no training group), 13 (54%) of the 24 patients had recurrent distortions during the study period, and six (25%) felt instability of the ankle. The difference in the number of recurrent distortions is significant (p < 0.05). The difference in the number of patients with functional instability is also significant (p < 0.01). The decrease in edema is seen in Figure 2. There was no significant difference in the edema between the training and no training group after 1, 6, and 12 weeks. In the training group, one patient used tape during sports activities and three were still using an ankle brace. In the nontraining group, two patients used tape and three patients were using an ankle brace during sports activities. There was no difference between the two groups in the time it took before the patients were painless during walking and during sports (Table 2). The posttraumatic edema 1 week after the trauma was similar in the two groups. After 6 weeks, the edema had decreased significantly in both groups (p < 0.05), but there was no significant difference between the two groups. After 12 weeks, the edema had decreased further, but the difference in both groups compared with the edema after 6 weeks was not significant. Still, no significant difference between the two groups could be observed (Figure 2). DISCUSSION Edema To preserve ankle mobility, it is important to minimize the posttraumatic edema following ankle sprains (18). To diminish the edema and hematoma in the acute phase following the sprain, sprains should be treated by RICE (rest, ice, compression, and elevation). Nonsteroidal anti-inflammatory drugs given during the first week after the trauma have proven valuable in some studies with respect to joint tenderness (7,li'). In Volume 23 Number 5 May 1996 JOSPT

4 RESEARCH STUDY Difference in volume between injured and uninjured foot Training gmup No-training group Prolonged peroneal reaction time was found in patients with ankle instability. Weeks post injury Week 1 week 6 week 12 FIGURE 2. Difference in volume (X 2 SD) between injured and uninjured foot 1, 6, and 12 weeks postinjury. this study, we chose not to give antiinflammatory drugs, because this would probably influence the measurements of the edema and hematoma. According to our study, early mobilization on the wobble board does not seem to affect the time course reduction of the edema. Muscular and Coordination Training Tropp (20) found that wobble board training during a 10-week period could improve pronator muscle strength in patients with functional instability. Further training did not give any added effect. With Tropp's conclusion in mind, our patients were trained for a 12-week period. His patients were trained for 5 minutes, three times a week. In our study, patients were trained daily according to a written program (Table 1). Furthermore, Tropp found a significant prophylactic effect of wobble board training in soccer players in the form of a reduction in the number of subsequent ankle sprains (20). It has been established that functional instability due to propriocep tive deficit also gives rise to an impaired ability to maintain postural control during single limb stance. Prolonged peroneal reaction time was found in patients with ankle instability (14,15). Comparative studies of wobble boards have shown that circular wobble boards with a diameter of 350 mm placed on a ball with 50 mm of curvature were most efficient in stimulating the lower limb muscles in electromyographic studies (4). The wobble boards in our study had a diameter of 350 mm and the height of the ball was 50 mm. The aim of functional training is to preserve the musculature and coordination of the musculature around the ankle joint without stressing the ligaments beyond their limits To diminish the stress, some recommend the use of an ankle brace (5,12). Early mobilization has been found to be effective in offering the most rapid return to normal function (2). It has been proposed that functional instability is usually due to motor incoordination following articular deafferentation and that that sequel could have been prevented by functional training (1,8,11,16). Consistent with these results, our study proves that early functional training is important in preventing recurrent distortions and the development of functional instability of the ankle, primarily in stage 2 sprains. Furthermore, this treatment did not adversely affect the edema and did not cause excessive pain. SUMMARY Wobble board training for a period of 12 weeks, beginning l week after the ankle sprain, was effective in reducing the number of recurrent distortions and in preventing functional instability of the ankle in pa- weeks Postinjury Pain at rest (percent of patients) Pain at walking (percent of patients) Pain at sports (percent of patients) Week 1 Training No Training Traininn TABLE 2. Number of patients in the training group and no training group with pain at rest, during walking, and pain at sports. Week Week 12 Training Training No Training JOSn Volume 23 Number 5 May

5 RESEARCH STUDY tients with primary ankle sprains. No difference in the edema or hematoma was seen during the recovery period when comparing the training group with the no training group 1, 6, and 12 weeks after the sprain. With the aim of reducing the number of patient.. with functional instability following primary distortions, we recommend wobble board training for patients who are active in sports. JOSF'T REFERENCES Bohannon RW, Larkin PA: Passive ankle dorsiflexion increases after a regimen of tilt table wedge board standing. Phys Ther 65: , ~ Brooks SC, Potter BT, Rainey JB: Treatment for partial tears of the lateral ligament of the ankle. Br MedJ 282: , 1981 Brostrom L: Sprained ankles. Treatment and prognosis in recent ligament ruptures. Acta Chir Scand l32: , 1966 Burton AK: Trunk muscle activity in- duced by three sizes of wobbleboards. J Orthop Sports Phys Ther 8:27-29, 1986 Carne P: Nonsurgical treatment of ankle sprains using the modified Sarmiento brace. Am 1 Sports Med l7: , 1989 Diamond JE: Rehabilitation of ankle sprains. Clin Sports Med 8: , Dupont M, Beliveau P, Theriault G: The efficacy of antiinflammatory medication in the treatment of the acutely sprained ankle. Am 1 Sports Med 15: 41-45, 1987 Freeman MAR, Dean MRE, Hanham WF: The etiology and prevention of functional instability of the foot. J Bone Joint Surg 47B: , 1965 Freeman MAR, Wyke B: Articular reflexes at the ankle joint. Br ] Surg 54: , 1965 Greene TA, Roland GC: A comparative isokinetic evaluation of a functional ankle orthosis on talocalcaneal function. ] Orthop Sports Ph ys Ther 1 1 : , lhara H, Nakayama A: Dynamic joint control training for knee ligament injuries. Am J Sports Med 14: , 1986 Jackson JP, Hutson MA: Cast-brace treatment of ankle sprains. Injury 17: , Kannus P, Renstrom P: Treatment for acute tears of the lateral ligament of the ankle. ] Bone Joint Surg 73A: , Karlsson J: Chronic lateral instability of the ankle joint. Unpublished master's thesis, Sahlgrenska University, Goteborg, Sweden, Konradsen L, Ravn JB: Prolonged peroneal reaction time in ankle instability. 1nt J Sports Med l2: , Lane SE: Severe ankle sprains. Phys Sportsmed l8:43-5 1, McLatchie GR, Allister C, MacEwen C, Hamilton G, Macgregor H, Colquhuon I, Pickvance N]: Variable schedules of ibuprofen for ankle sprains. Br J Sports Med 19: , Namba RS, Kabo JM, Dorey FJ, Meals RA: Continuous passive motion versus immobilisation. Clin Orthop 267: , Prins JG: Diagnosis and treatment of injury to the lateral ligament of the ankle. A comparative clinical study. Acta Chir Scand Suppl 486, 1978 (abstract) 20. Tropp H: Functional instability of the ankle joint. Medical dissertation, Link~ping University, 1985 Volr~me 23 Number 5 Mav 1W6 JOSIT