1 - Resident Physician in Orthopedics and Traumatology, Paulista School of Medicine, Federal University of São Paulo, São Paulo, SP.
2 - Resident Physician in Thoracic Surgery, Paulista School of Medicine, Federal University of São Paulo, São Paulo, SP.
3 - MSc in Sciences from Paulista School of Medicine, Federal University of São Paulo; Attending Physiotherapist at the Sports Traumatology Center (Cete), São Paulo, SP.
4 - MSc in Sciences, Attending Physician in the Spine Group, Paulista School of Medicine, Federal University of São Paulo, and at the Sports Traumatology Center (Cete), São Paulo, SP.
5 - Postgraduate Student and Attending Physician in the Spine Group, Paulista School of Medicine, Federal University of São Paulo, and at the Sports Traumatology Center (Cete), São Paulo, SP.
6 - Full Professor and Head of the Spine Group, Paulista School of Medicine, Federal University of São Paulo, São Paulo, SP.
Work performed in the Department of Orthopedics and Traumatology, Paulista School of Medicine, Federal University of São Paulo.
Correspondence: Rua Dr. Diogo de Faria 1201, Ap. 146, São Paulo, SP. E-mail: carla.chertman@gmail.com
Over recent decades, there have been great efforts towards improvements in the performance and results attained by athletes, within sports. Coaches have been accompanied by physical trainers and the demands on athletes have increased. Within this new reality, it has been seen that athletes have been consulting physicians because of a variety of ailments relating to sports practice. Thus, a need for better understanding of diseases relating to this specific public has been created.
With regard to the lumbar spine, measuring its range of motion has always been important for physicians and physiotherapists. This evaluation forms part of orthopedic physical examination, since limitations on movement have a variety of clinical correlations. For example, disc fractures or hernias leading to changes in flexion and to spondylosis, spondylolisthesis or canal stenosis may occur, thus giving rise to changes in extension movements(1). Although range-of-motion examinations are nonspecific, they identify spinal diseases at different levels and thus also serve as an instrument for assessing the therapeutic response.
Thomas et al(2) measured lumbar range of motion and concluded that there was an association between measures that restricted the range of motion and occurrences of lumbar pain. Mayer et al(3) measured the range of motion in individuals with and without lumbar pain. Fitzgerald et al(4) demonstrated the relationship between the range of motion and age. Ensink et al(5) described how range-of-motion measurements changed according to the time of day because of loss of height of the intervertebral discs.
A variety of instruments have been used in practice for assessing lumber range of motion, and also in studies in the literature. Simple radiography is considered by many authors to be the standard method for such measurements(6,7), but new methods have been proposed with the aim of establishing therapeutic follow-up parameters without excessive exposure of patients to radiation. Clinical methods have gained space in the literature, such as proposals for economically viable, reproducible and harmless alternatives that are reproducible and harmless, as is the case with long goniometry.
Two factors of importance in studying lumbar range of motion can also be added: measurements on the popliteal angle and the hamstrings. Gajdosik et al(8) concluded that flexion measurements on the lumbar range of motion between groups of individuals with short and long hamstring muscles differed significantly.
The present study aimed to compare normal rangeof- motion values for trunk flexion and extension between athletes and non-athletes, determine the mean interval of the value for athletes using the goniometer method, and correlate these data with the popliteal angle and hamstring tests.
METHODS
Subjects
This study was conducted between July 2002 and August 2003 and included the participation of a total of 100 individuals, who were divided equally into two groups: athletes and non-athletes. Individuals were considered to be athletes if they practiced a sports activity in a non-sporadic manner, consisting of a minimum of six hours of training a week with specialized monitoring, along with regular participation in competitions. Individuals were considered to be non-athletes if they did not regularly practice any physical activity. Individuals of both sexes aged between 14 and 45 years, without any painful lumbar symptoms, were included in both groups. The exclusion criteria for both groups were: previous lumbar surgery, painful symptoms in regions adjacent to the spine that would interfere with carrying out the test, difficulty in adapting to the measurement instruments and non-consent to the study objectives among the participants.
The examiners contacted the coaches of athletes who were being monitored at the sports traumatology center of our institution, and requested these athletes' presence prior to their regular training sessions. The group of nonathletes was composed of school and university students in the city of São Paulo who fulfilled the criteria.
All the participants in this study read and signed the free and informed consent statement, and for those who were under the age of 18 years, consent and signatures were obtained from the adults legally responsible for them.
PROCEDURES
The measurements were always made in the afternoons by two examiners who had previously been instructed about how to carry out the tests. The flexion and extension measurements on the lumbar spine were obtained consecutively by the two examiners, using a simple goniometer, such that all the volunteers performed each movement twice. To avoid the variations described by Ensink apud Thomas et al(2), consecutive measurements were made during the same period of the day.
The evaluations on the flexion and extension range of motion of the lumbar spine were made using a simple goniometer after instructing the volunteer regarding positioning and the correct way of doing the test.
The individuals began the test in an upright standing position, with the knees completely extended and arms in front of the body (Figure 1). Then, upon a verbal command from the examiner, they made slow and gradual movements for flexion (Figure 2) and extension (Figure 3) as far as the maximum amplitude, at which point the goniometer measurement was made. To evaluate lumbar flexion, the arms had to be flexed at 90 degrees, and to evaluate lumbar extension, the arms had to be kept fixed behind the neck. For these measurements, the iliac crest was taken as the fixed reference point, while the mobile point used was the axillary line collateral to the iliac crest anteriorly, such that the fixed arm of the goniometer remained central in the lateral region of the trunk.
To evaluate the flexibility of the hamstring muscles, two tests were used: popliteal angle and arm reach. The volunteers began in a lying down position, with the leg under evaluation flexed at 90 degrees at the hip and
Figure 1 - Individual's initial position and emplacement of goniometer
Figure 2 - Maximum flexion and measurement with goniometer
Figure 3 - Maximum extension and measurement with goniometer
knee, and the other leg extended on the bed. Upon a verbal command from the examiner, they actively extended the knee until encountering natural resistance.
The popliteal angle was also evaluated using the simple goniometer, and for this measurement, the lateral joint interline of the knee was taken as the fixed reference point, the lateral malleolus was taken as the reference point for the mobile arm of the goniometer and the central lateral region of the thigh was taken as the reference point for the fixed arm of the goniometer.
The arm reach test was carried out with the volunteers initially in a seated position, with extended knees supported on a platform in order to keep the ankles in a neutral position. The individuals then performed trunk flexion with the aim of reaching out as distally as possible with the arms. Using an ordinary measuring tape (marked in centimeters), the distance between the reached-out distal tip of the third finger and the zero point on the platform (heel position) was measured. If the fingers did not reach the zero point, the distance was recorded as a negative value, while if they reached beyond the zero point, the distance was recorded as a positive value.
The quantitative variables were represented by means and standard deviations, and the qualitative variables by absolute and relative frequencies.
The presence of correlations between the parameters studied was evaluated using Pearson's correlation coefficient (r) and its significance was tested.
Student's t test was used for independent samples and for comparing the groups of athletes and non-athletes in relation to all of the parameters of interest. The same method was used for analyzing the goniometry in relation to the parameters, and for comparing the measurements obtained by examiners 1 and 2.
The significance level of 0.05 (5%) was used, and descriptive levels (p) lower than this value were considered significant and represented by *.
RESULTS
Characterization of the samples
The samples were formed by 50 athletes and 50 nonathletes, who were all volunteers. The athletes' group consisted of 31 women (62%) and 19 men (38%), with ages ranging from 14 to 40 years and a mean of 21 years (SD = six years). Among the 50 athletes, 28 (56%) were whites, 13 (26%) were black and nine (18%) were mixed. The distribution of the athletes according to the sport practiced was: 12 athletics participants (24%), two basketball players (4%), one boxer (2%), one cyclist (2%), three football (soccer) players (6%), one indoor football (soccer) players (2%), 12 handball players (24%), two judo players (4%), three karate players (6%), one swimmer (2%), one table tennis player (2%), one triathlete (2%) and 10 volleyball players (20%).
The length of time of sports practice ranged from two to 22 years, with a mean of eight years (SD = five years). The length of training time per week ranged from six to 36 hours, with a mean of 16 hours (SD = seven hours).
The right side was the dominant side for 39 of the athletes (78%), while it was the left side for eight athletes (16%) and three athletes (6%) were ambidextrous.
The group of non-athletes was formed by 37 women (74%) and 13 men (26%). Their ages ranged from 17 to 28 years, with a mean of 21 years (SD = two years). All 50 of the non-athletes were white.
Correlation between hamstring and popliteal angle measurements and other parameters among the athletes
The measurements of the right and left popliteal angles did not show any statistically significant correlation with the hamstring measurements and parameters measured using goniometry (p > 0.05) in the group of athletes. In other words, increases in the popliteal angle measurements did not signify increases in the measurements obtained using goniometry or the hamstring measurements (Table 1).
A statistically significant correlation was found between the hamstring measurements and the parameters measured in flexion using goniometry (p < 0.05). The correlations were positive, thus indicating that the greater the hamstring measurements were, the greater the measurements obtained in flexion using goniometry also were. On the other hand, for the parameters measured in extension using goniometry, Table 2 shows that no statistically significant correlation with the hamstring measurements was found (p > 0.05).
Correlation between hamstring and popliteal angle measurements and other parameters among the non-athletes
In the group of non-athletes, a statistically significant correlation was found between the right and left popliteal angle measurements and the hamstring measurements and parameters measured by goniometry (p < 0.05). The correlations were positive, thus indicating that the greater the angle measurements were, the greater the hamstring measurements and measurements obtained using goniometry in flexion and in extension (Table 3).
A statistically significant correlation was found between the hamstring measurements and the parameters measured in flexion and extension using goniometry (p < 0.05). The correlations were positive, thus indicating that the greater the hamstring measurements were, the greater the measurements in flexion and extension obtained using goniometry also were (Table 4).
Comparison between the groups of athletes and non-athletes
No statistically significant differences were found between the groups of athletes and non-athletes in relation to the parameters of popliteal angle and goniometer in extension (p > 0.05).
In relation to the parameters of hamstrings and goniometer in flexion, a statistically significant difference was found between the groups of athletes and non-athletes (p < 0.05). For all the parameters, the group of athletes presented a significantly greater mean than that of the group of non-athletes (Table 5).
Comparison between the examiners A1 and A2 in the group of athletes
A statistically significant difference was found between the examiners A1 and A2 in relation to the parameters of goniometer in flexion and goniometer in extension (p < 0.05). For the parameters of goniometer in flexion, the means obtained from the measurements of examiner A1 were shown to be significantly lower than those of examiner A2. For the parameter of goniometer in extension, the means obtained from the measurements of examiner A1 were shown to be significantly greater than those of examiner A2 (Table 6).
Comparison of flexion between examiners A1 and A2 in the group of non-athletes
A statistically significant difference was found between the examiners A1 and A2, in relation to the parameter of goniometer in extension (p < 0.05).
For the parameter of goniometer in extension, the mean obtained from the measurements made by examiner A1 were found to be significantly greater than those of examiner A2. No statistically significant difference was found between examiners A1 and A2 in relation to the parameter of goniometer in flexion (p > 0.05) (Table 7).
DISCUSSION
In this study, it was observed that trunk flexion presented higher values among individuals who practiced sports. This has importance in detecting spinal diseases, and in the response among individuals undergoing treatment.
In a study using goniometers, Boone et al(9) concluded that this was a dependent evaluative method, although their study was limited to arm and leg joint, and the lumbar spine was not tested. In fact, the movement of the lumbar spine is a challenge for the equipment, given that the spine has multiple joint axes with positions that change during the movement(10). The long goniometer is a piece of apparatus composed of two transparent jointed flat arms measuring 50 cm that measure the range of motion in degrees. Although this equipment is mechanically precise and specific goniometers for different joints exist, studies on the validity and reliability of this equipment for measuring human movement are scarce. Moreover, there are theoretical limits relating to its use for the lumbar spine, given that this is an instrument with a simple folding action that keeps its axis fixed during the movement. As mentioned earlier, the axis of the lumbar spine changes its position during the movement(10).
Mayerson and Milano(11) found fluctuation of 4º between measurements, thus placing doubt on the reliability of the method, but suggesting that it might be reliable under well-defined circumstances. Fitzgerald et al(4) used a goniometer to measure spinal range of motion, but with a technique that combined it with the technique of spinal traction. They found inter-observer reliability, but this result was based on data from 17 young adults, such that the authors themselves considered that there were limitations in generalizing the result to a broader age range.
Based on our results and on a review of the literature, we consider that goniometry is a reliable method. However, we believe that its use should be limited to analysis of the response to treatment, and we reaffirm that in such cases, all the measurements should be made by the same professional. With regard to detection of spinal diseases, we believe that new studies with other methods or with a greater number of volunteers should be carried out in order to elucidate this issue.
Regarding trunk extension values, we did not find any difference between the groups or athletes and nonathletes. Perhaps other studies might better define the behavior of this measurement among athletes, or perhaps there is a better method for measuring it. In an analysis on range of motion using an inclinometer, Saur et al(6) did not find any correlation with extension measurements made by means of radiology.
CONCLUSION
With regard to hamstring measurements, we agree with the literature in that we observed that there was a positive correlation between these measurements and those obtained using a goniometer in flexion. Furthermore, through noting that there is a difference between the groups of athletes and non-athletes regarding this measurement, our study suggests that hamstring measurements should be taken into consideration when considering athletes' range of motion in investigations on disorders. On the other hand, the popliteal angle measurements showed a correlation pattern differing from the other measurements between the groups of athletes and non-athletes, such that we suggest that new studies should try to elucidate this matter.
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