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TitleA Multi-station Proprioceptive Exercise Program in Patients With Ankle Instability
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A multi-station proprioceptive exercise
program in patients with ankle instability

ERIC EILS and DIETER ROSENBAUM

Funktionsbereich Bewegungsanalytik (Movement Analysis Lab), Klinik und Poliklinik fuer Allgemeine Orthopaedie,
Westfaelische Wilhelms-Universitaet Muenster, Muenster, GERMANY

ABSTRACT

EILS, E., and D. ROSENBAUM. A multi-station proprioceptive exercise program in patients with ankle instability. Med. Sci. Sports
Exerc., Vol. 33, No. 12, 2001, pp. 1991–1998. Purpose: The aim of the present study was to investigate the effects of a 6-wk
multi-station proprioceptive exercise program that is easy to integrate in normal training programs. Methods: Patients with chronic
ankle instability were used, and results of three testing procedures before and afterward were compared: joint position sense, postural
sway, and muscle reaction times to sudden inversion events on a tilting platform. A total of 30 subjects with 48 unstable feet were
evaluated (exercise group: N � 31; control group: N � 17). Results: In the exercise group, the results showed a significant improvement
in joint position sense and postural sway as well as significant changes in muscle reaction times. Conclusion: Based on the present
results, a multi-station proprioceptive exercise program can be recommended for prevention and rehabilitation of recurrent ankle
inversion injuries. Key Words: ANKLE INSTABILITY, ELECTROMYOGRAPHY, PROPRIOCEPTION, COORDINATION, PER-
ONEAL REACTION TIME

A
nkle inversion sprains are frequent injuries in sports
and activities of daily living that mostly concern
young physically active individuals (1,10). It has

been estimated that the incidence is about one ankle inver-
sion per 10,000 people per day (4). Ankle ligament injuries
constitute between 15 and 45% of all sports-related injuries

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data revealed no significant differences between the groups (Table
1). Many subjects (55%) revealed a bilateral instability so that 48
feet were evaluated (EG, N � 31; CG, N � 17). The study was
approved by the institution’s human ethics committee and before
participation, all subjects were informed about the procedures and
signed an informed consent form.

Test procedures. The order of the three testing proce-
dures was predetermined to minimize the effects between
tests and the effect of fatigue. Joint position sense testing
was performed first, followed by balance and reflex testing.
Both feet were tested in the week before and after the 6-wk
exercise period. The tests were repeated in the same manner.
One year after the exercise period, the frequency of inver-
sion sprains was reevaluated with a questionnaire that was
sent to all subjects.

Joint position sense (JPS). A custom-built device
was used for testing the joint position sense in a passive
angle reproduction test. It consisted of a footplate in
combination with a Penny & Giles goniometer (Biomet-
rics Ltd, Gwent, UK). Subjects sat in front of the mea-
suring device and placed the foot on the horizontal foot-
plate (Fig. 1). The rotation axis of the ankle was aligned
with the medial malleolus. The knee joint was placed
over the ankle. This position was defined as the neutral
position (0°). Subjects were unable to see their feet
throughout the examination and had their eyes closed to
concentrate on the measurements. For the passive angle
reproduction, the foot was brought into one of the four
testing positions (10°, 20° dorsiflexion, 15°, and 30°
plantarflexion) and was held for 2 s. Then it was brought
back in neutral position and back toward the testing
position until the subjects indicated that they felt they had
reached the same position. The foot was brought back in
neutral position, and the next angle was chosen. Angles
were given in random order and each angle was tested six
times. All joint position tests were performed by the same
investigator. The difference of all predefined and repro-
duced angles was saved for analysis.

Postural sway (PS). A Kistler force plate was used to
measure the postural sway in single-limb stance. No infor-
mation concerning the posture was given to the subjects
except to avoid contact of the legs and to focus on a point
on the wall directly ahead (Fig. 2). The individual posture
was noted by the investigator, and subjects were informed to
use the same style as in the pretest when it deviated in the
posttest. For each foot six trials of single-limb stance (15 s
each) were performed. For analysis, the sway of the center
of gravity (CoG) in the xy-plane in medio-lateral and antero-

posterior direction as well as the sway distance were aver-
aged over six trials.

Muscle reaction times (MRT). A customized trap
door with a 30° tilting angle in the frontal plane was used to
simulate lateral ankle sprains (Fig. 3). Subjects stood up-
right on the platform with one foot on the hinged trapdoor
bearing most of the body weight. The axis of rotation of the
trapdoor was just medial of the weight-bearing foot, and the
other foot was placed only with the toes in contact to the
trapdoor to maintain balance. Surface EMG signals were

FIGURE 1—Testing of joint position sense.

TABLE 1. Anthropometric data of the experimental and the control group.

Experimental Group Control Group

P LevelMean � SD Range Mean � SD Range

Age (yr) 27.0 � 7.7 14–47 26.4 � 4.9 16–34 NS
Weight (kg) 69.6 � 13.4 50–98 75.7 � 12.2 64–99 NS
Height (cm) 176.6 � 10.8 160–198 179.7 � 9.9 164–194 NS
Sex (m/f) 6/14 6/4
Sports activity (per week) 5.2 � 3.1 1–12 4.5 � 1.5 3–8 NS
Frequency of ankle sprains (per yr) 27.6 � 26.8 4–104 19.3 � 18.1 4–52 NS

1992 Official Journal of the American College of Sports Medicine http://www.acsm-msse.org

Page 4

Haramed®, and Biodex®. Alternatively, devices with a com-
parable stimulation mode can be used.

Subjects started each exercise period with a 5- to
10-min warm-up program. The exercise period took 20
min, and single exercises were performed for 45 s fol-
lowed by a 30-s break where subjects moved over to the
next station. The whole program was performed twice to
exercise both feet in the same way. In the first session, the
correct posture of the lower leg of the subjects was
controlled (slight external rotation of the foot, slightly
flexed knee, and the patella over the metatarsophalangeal
joint) during the exercise. The intensity of the 6-wk
training period was increased by small modifications for
each station every 2 wk (Table 2). The main goal of this
program was to generate a wide variation of different
stimuli for strength and coordination. In addition, many
stations were set up to have the possibility to train many
persons simultaneously to easily include this program in
normal training programs of teams of athletes or groups
of patients. A more detailed description of the exercise
program is given elsewhere (25).

RESULTS

In the angle reproduction test, an improvement for all
testing conditions in the exercise group was found after the
exercise period (Table 3). Except for 10° dorsiflexion (P �
0.057), all improvements were significant. The greatest
changes were seen at 15° and 30° plantarflexion and for the
mean of the four testing positions. The control group
showed only slightly improved values, but none of the
differences were significant.

In the postural sway measurements, an improvement after
the exercise program was found for all parameters in the
experimental group as well as for the control group (Table
4). Sway in the medio-lateral direction was smaller than in
the antero-posterior direction for both groups. In the medio-
lateral direction, the standard deviation and the maximum
sway showed a significant improvement in the exercise
group but not in the control group. In the antero-posterior
direction, significant improvements were not found in the
experimental group but in the control group (P � 0.05). The
overall sway distance of the center of gravity (CoG) was
reduced in both the exercise (P � 0.01) and the control
group (P � 0.01).

Muscle reaction times were in the range of 62–74 ms and
were prolonged between pre- and posttest in both groups for
all muscles (Table 5). For peroneus longus and peroneus
brevis, the difference of approximately 3 ms was significant
(P � 0.001). No significant differences could be detected
for tibialis anterior and for all muscles in the control group.

IEMG showed not consistent results in both groups. In the
experimental group, there was a slightly increased muscular
response in the peroneal muscles and a slight decrease for
the tibialis anterior. In the control group, peroneus longus
and tibialis anterior activity increased, whereas peroneus
brevis decreased. None of these changes were significant
(Table 5).

A total of 90% of the subjects of the exercise group
returned the questionnaire 1 yr after training. Evaluation
showed a significantly reduced frequency of ankle inver-
sions after the exercise program of almost 60% (from 27.6
to 11.2 times per year, P � 0.001). No patient reported an
increased frequency of ankle sprains and most subjects
reported a better feeling of stability and safety. A total of
10% of the subjects reported to perform proprioceptive
exercises at home and did not report any ankle sprains after
the exercise program.

DISCUSSION

The aim of the present study was to investigate the effects
of a multi-station proprioceptive exercise program obtained
with three different testing procedures. We expected that
this program would lead to an improvement of propriocep-
tive capabilities in the exercise group and therefore to im-
proved functional stability and a decrease in the frequency
of recurrent ankle sprains.

Based on the positive subjective results of reduced fre-
quency of ankle sprains and a better feeling of stability after the

FIGURE 4—Definition of reaction times to simulated sudden ankle
inversion for peroneal muscles and tibialis anterior. The dotted line
indicates the beginning of the tilting movement and the double arrow
the reaction time for each muscle.

1994 Official Journal of the American College of Sports Medicine http://www.acsm-msse.org

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