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Changes in lumbar lordosis in young patients with low back pain during a 10-year period
J Orthop Sci (2002) 7:618–622
Changes in lumbar lordosis in young patients with low back pain during a 10-year period Yasuaki Murata, Takehiko Utsumi, Eiji Hanaoka, Kazuhisa Takahashi, Masatsune Yamagata, and Hideshige Moriya Department of Orthopaedic Surgery, School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8677, Japan
Abstract Height and muscle strength have reportedly changed among Japanese youth during the past 10 years. Height has increased, and the back muscles have become weaker than 10 years ago. We compared the lumbar lordosis of youth today (113 men and 76 women) and of 10 years ago (85 men and 62 women). Lumbar lordosis and sacral inclination were measured on lateral standing radiographs of the lumbar spine. We also measured the same parameters among adults today (63 men and 63 women) and 10 years ago (56 men and 73 women) to study postural changes in another generation. In both men and women, the lumbar lordosis and the sacral inclination of youth today were approximately 10° larger than they were 10 years ago (P ⬍ 0.0001). However, there was no significant difference between the values among adults today and those of the same generation 10 years ago.
It is desirable to investigate asymptomatic volunteers for the longitudinal study of postural change. However, there is some difficulty in carrying out radiographic examinations in healthy subjects. Thus, in the present study, we planned a radiographic measurement study for patients with slight low back pain as the first step. The present study was undertaken to compare the posture of youth today and that of the same generation 10 years ago, by measuring lumbar lordosis and sacral inclination in lateral standing radiographs of the lumbar spine, and to discuss problems that have occurred among youth.
Subjects and methods Key words Lumbar spine · Lordosis · Youth
Introduction The muscles and ligaments around the lumbar spine may influence posture. Such postural changes can be a source of low back pain. Although there are several reports discussing the relation between low back pain and lumbar spinal alignment,1–11,13,14 there are no reports on postural changes in the younger generation in Japan. The physical constitution of youth has reportedly changed during the past 10 years.12 Height and weight have increased as compared with previous findings. In contrast, muscle strength, such as that of the back muscles, is reported to be weaker than it was 10 years ago. These changes, and the consequent imbalance, may cause changes in spinal alignment.
Offprint requests to: Y. Murata, Linnégatan 45, Apartment nr: 107 SE-413 08 Gothenburg, Sweden Received: March 25, 2002 / Accepted: June 12, 2002
Three hundred and thirty-six Japanese youth (198 men and 138 women), whose ages ranged from 12 to 20 years, were included in this study. The subjects were composed of four groups: group Am, 85 young men (mean age, 16.2 ⫾ 2.2 years) who had low back pain and underwent radiographic examination of the lumbar spine in a standing position during the period from 1985 to 1988; group Af, 62 young women (mean age, 16.2 ⫾ 2.4 years) from 1985 to 1988; group Bm, 113 young men (mean age, 15.8 ⫾ 2.1 years) from January 1999 to June 1999; and Group Bf, 76 young women (mean age, 15.9 ⫾ 2.1 years) from January 1999 to June 1999. The exclusion criteria of the subjects were scoliosis, kyphosis, spondylolysis, and spondylolisthesis. In addition, we graded the symptoms, with 15 points representing full marks, using parts I and II of the Japanese Orthopaedic Association (JOA) score. Subjects were limited to those with rather minor pain that could be treated without spinal surgery. To obtain accurate lateral radiographs of the lumbar spine, the patient’s knees were extended as much as possible, the hips were aligned perpendicular to the film, the legs and feet positioned close together, and the arms were held out straight and supported by
Y. Murata et al.: Lumbar lordosis in youth
gripping a bar, in accordance with previous studies.6–10,12 Each lateral radiograph was independently measured by two observers, using Cobb’s method.1–11,13,14 Lumbar lordosis was measured as the angle between the superior endplate of L1 and the superior endplate of S1; sacral inclination was measured as the angle between the superior endplate of S1 and a horizontal line. We also measured the angles in randomly selected members of an other generation, with the subjects being 129 adults (56 men and 73 women, mean age, 53.1 ⫾ 11.4 years; range, 21–79 years) who underwent radiographic examination with the same procedure during the period from 1985 through 1988 (groups Cm and Cf), and 126 adults (63 men and 63 women; mean age, 57.2 ⫾ 13.5 years; range, 21–79 years) during the period from 1998 through June 1999 (groups Dm and Df). The adult subjects were also limited to those with rather minor pain which could be treated without spinal surgery. Statistical analysis was performed using Student’s t-test. All probability values were calculated within a confidence interval of 95%.
Results Intraobserver variance ranged from 0° to 5.0° with an average of 1.7° (95% confidence limit, ⫾1.5°), and interobserver variance ranged from 0° to 9.0°, with an average of 2.6° (95% confidence limit, ⫾2.3°). The average JOA score was 11.8 ⫾ 2.0 in group Am, 12.1 ⫾ 1.6 in Af, 11.7 ⫾ 2.1 in Bm, and 12.0 ⫾ 1.9 in Bf. The
619
average JOA score was 11.0 ⫾ 2.4 in group Cm, 11.5 ⫾ 2.3 in Cf, 10.8 ⫾ 2.4 in Dm, and 11.3 ⫾ 2.4 in Df. There were no statistically significant differences among them (15 points full marks). Mean values for the measurements in each group are shown in Fig. 1. Both the lordotic angle and sacral inclination were significantly larger in group Bm than in Am (P ⬍ 0.0001), and in Bf they were also significantly larger than in Af (P ⬍ 0.0001). However, there was no significant difference between Cm and Dm, or between Cf and Df. With regard to sex, regarding the lordotic angle, there was no significant difference between Am and Af, Cm and Cf, or Dm and Df, although the angle in Bm was significantly larger than that in Bf (P ⬍ 0.01). The mean values in each age group are shown in Fig. 2. Both the mean lordotic angle and sacral inclination were significantly larger in Bm than in Am at ages 13 to 19 years (P ⬍ 0.05).
Discussion Many authors have paid attention to the relation between lumbar lordosis and low back pain in their reports. It is suggested that the loss of lordosis in the lumbar spine is associated with low back pain.6,7,10,12,13 Some authors stated that, in a position in which the lordosis decreases, intradiscal pressure will consequently increase, and the increased intradiscal pressure may become the underlying factor for the low back pain.1,9 However, the relation between the degree of low
b
a Fig. 1. a Each bar shows the mean lordotic angle. The angle was significantly larger in group Bm than in Am (P ⬍ 0.0001), and was also significantly larger in Bf than in Af (P ⬍ 0.0001). However, there was no significant difference among Cm, Cf, Dm, and Df. With regard to sex, there was no significant difference between Am and Af, although the angle in Bm was significantly larger than in Bf (P ⬍ 0.01). There was no significant difference in lordotic angle among groups Am, Af, Cm, Cf, Dm, and Df. b Each bar shows the mean sacral inclination. The angle was significantly larger in group Bm than in Am (P ⬍ 0.0001), and was also significantly larger in Bf than
in Af (P ⬍ 0.0001). However, there was no significant difference among Cm, Cf, Dm, and Df. Group Am, Eighty-five young men with low back pain who underwent radiographic examination of the lumbar spine during the period from 1985 to 1988; group Af, 62 young women from 1985 to 1988; group Bm, 113 young men from January 1999 to June 1999; group Bf, 76 young women from January 1999 to June 1999; group Cm, 56 adult men from 1985 through 1988; group Cf, 73 adult women from 1985 through 1988; group Dm, 63 adult women from 1998 through June 1999; group Df, 63 adult men from 1998 through June, 1999
620
a
Y. Murata et al.: Lumbar lordosis in youth
b
Fig. 2. a The mean lordotic angles in each age group are shown. The mean lordotic angle was significantly larger in group Bm (today) than in Am (10 years ago) at ages 13 to 19 years (P ⬍ 0.05). b The mean sacral inclinations in each age group are shown. The mean angle was significantly larger in group Bm than in Am at ages 13 to 19 years (P ⬍ 0.05)
Fig. 3. Each bar shows the mean height of men and women in 1985 (white bars), 1990 (diagonally striped bars), 1995 (vertically striped bars), and 1998 (black bars), at ages 12 to 17 years. The graphs clearly show that the values are gradually increasing in each age group. The data are quoted from a 1999 government publication12
Fig. 4. Each bar shows the mean back muscle strength of men and women in 1985 (white bars), 1995 (diagonally striped bars), and 1997 (black bars) at ages 12 to 17 years. They indicate that the values are gradually decreasing in each age group. The data are quoted from a 1999 government publication12
back pain and sagittal lumbar alignment have not been examined. Likewise, although the present study clarified the postural changes of patients with low back pain, we failed to consider the degree of low back pain. Long follow-up studies on an asymptomatic population are yet to be conducted for further classification. The living environment and lifestyles are rapidly changing in Japan. These changes may lead to changes in physique and muscle strength.9 According to a 1999 government publication,12 the mean height of Japanese youth has increased for the past 13 years (Fig. 3). The
mean weight has also increased during the same period. Conversely, back muscle strength has decreased for the past 12 years (Fig. 4). The range of trunk extension has also become more limited (Fig. 5). The data indicate that muscle strength around the lumbar spine has become weaker than before. This change can be a factor influencing alignment of the lumbar spine. Furthermore, the range of standing trunk flexion, which reflects the flexibility of the trunk, has become more limited (Fig. 6). Both trunk extension and standing trunk flexion have a relation to lumbar spine motion.
Y. Murata et al.: Lumbar lordosis in youth
621
Fig. 5. Each bar shows the mean value of trunk extension (ext.) of men and women in 1985, 1995, and 1997 at ages 12 to 17 years. Bars, As in Fig. 4. The values show a tendency to decrease in each age group. The data are quoted from a 1999 government publication12
Fig. 6. Each bar shows the mean value of standing trunk flexion ( flex.) of men and women in 1985, 1995, and 1997 at ages 12 to 17 years. Bars, As in Fig. 4. The values have a tendency to decrease in each age group. The data are quoted from a 1999 government publication12
Regarding Japanese youth today, we can say that their physique is larger, the muscle around the lumbar spine is weaker, and the pliability of the lumbar spine has decreased. It is reasonable to consider that changes in balance will influence the posture. Although the present study clarified the postural changes of patients with low back pain, these quoted data on physique and muscle strength are those of an asymptomatic population. We failed to consider the height, weight, and muscle strength of our subjects. Long follow-up investigations on an asymptomatic population are yet to be conducted for further studies. In the present study, the change was shown as an increase in lumbar lordotic angle and sacral inclination. These may be aspects of postural changes among youth people. Changes in physique, muscle strength, pliability, and posture may be affected by lifestyle. Multiple factors, including activity, eating habits, and living environment, may be cited as causes of the changes. For example, as regards the activity of young people, students are
obliged to study hard from earlier ages than before, in order to get into higher level schools, because Japanese society tends to attach importance to one’s academic career. This social phenomenon is probably related to the lack of exercise among youth. Another related factor may be the development of transport facilities. The popularization of personally owned cars is also a probable cause of lack of exercise. Moreover, children used to play outside in the past. However, since computer games began to be sold about 20 years ago, and as the computer games propagated, the youth tended to play alone in a room, and not to play with friends outdoors. These factors may influence muscle strength among youth. The weakness of the muscles around the lumbar spine may be a cause of low back pain. These are probably only a few of the multiple factors that can influence young people. What is important in the treatment of low back pain among youth today may be to improve their lifestyles. We should carefully consider pathophysiology when we treat low back pain in young patients.
622
Y. Murata et al.: Lumbar lordosis in youth
References 1. Adams MA, Hutton WC. The effect of posture on the lumbar spine. J Bone Joint Surg Br 1985;67:625–9. 2. Bernhardt M, Bridwell KH. Segmental analysis of the sagittal plane alignment of the normal thoracic and lumbar spines and thoracolumbar junction. Spine 1989;14:717–21. 3. Chernukha KV, Daffner RH, Reigel DH. Lumbar lordosis measurement: a new method versus Cobb technique. Spine 1998;23:74– 80. 4. Gelb DE, Lenke LG, Bridwell KH, et al. An analysis of sagittal spinal alignment in 100 asymptomatic middle and older aged volunteers. Spine 1995;20:1351–8. 5. Hasday CA, Passoff TL, Perry J. Gait abnormalities arising from iatrogenic loss of lumbar lordosis secondary to Harrington instrumentation in lumbar fractures. Spine 1983;8:501–11. 6. Jackson RP, McManus AC. Radiographic analysis of sagittal plane alignment and balance in standing volunteers and patients with low back pain matched for age, sex, and size. A prospective controlled clinical study. Spine 1994;19:1611–8. 7. Jackson RP, Peterson MD, McManus AC, et al. Compensatory spinopelvic balance over the hip axis and better reliability in
8.
9.
10. 11.
12.
13.
14.
measuring lordosis to the pelvic radius on standing lateral radiographs of adult volunteers and patients. Spine 1998;23:1750– 67. Korovessis PG, Stamatakis MV, Baikousis AG. Reciprocal angulation of vertebral bodies in the sagittal plane in an asymptomatic Greek population. Spine 1998;23:700–5. Lee CS, Lee CK, Kim YT, et al. Dynamic sagittal imbalance of the spine in degenerative flat back. Significance of pelvic tilt in surgical treatment. Spine 2001;26:2029–35. Lord MJ, Small JM, Dinsay JM, et al. Lumbar lordosis. Effects of sitting and standing. Spine 1997;22:2571–4. Stagnara P, De Mauroy JC, Dran G, et al. Reciprocal angulation of vertebral bodies in a sagittal plane. Approach to references for the evaluation of kyphosis and lordosis. Spine 1982;7:335–42. Taka T. Statistical abstract of education, science, sports and culture. Tokyo: Printing Bureau, Ministry of Education, Science, Sports and Culture; 1999. p. 132–9. Vedantam R, Lenke LG, Keeney JA, et al. Comparison of standing sagittal spinal alignment in asymptomatic adolescents and adults. Spine 1998;23:211–5. Williams MM, Hawley JA, McKenzie RA, et al. A comparison of the effects of two sitting postures on back and referred pain. Spine 1991;16:1185–91.
Changes in lumbar lordosis in young patients with low back pain during a 10-year period Yasuaki Murata, Takehiko Utsumi, Eiji Hanaoka, Kazuhisa Takahashi, Masatsune Yamagata, and Hideshige Moriya Department of Orthopaedic Surgery, School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8677, Japan
Abstract Height and muscle strength have reportedly changed among Japanese youth during the past 10 years. Height has increased, and the back muscles have become weaker than 10 years ago. We compared the lumbar lordosis of youth today (113 men and 76 women) and of 10 years ago (85 men and 62 women). Lumbar lordosis and sacral inclination were measured on lateral standing radiographs of the lumbar spine. We also measured the same parameters among adults today (63 men and 63 women) and 10 years ago (56 men and 73 women) to study postural changes in another generation. In both men and women, the lumbar lordosis and the sacral inclination of youth today were approximately 10° larger than they were 10 years ago (P ⬍ 0.0001). However, there was no significant difference between the values among adults today and those of the same generation 10 years ago.
It is desirable to investigate asymptomatic volunteers for the longitudinal study of postural change. However, there is some difficulty in carrying out radiographic examinations in healthy subjects. Thus, in the present study, we planned a radiographic measurement study for patients with slight low back pain as the first step. The present study was undertaken to compare the posture of youth today and that of the same generation 10 years ago, by measuring lumbar lordosis and sacral inclination in lateral standing radiographs of the lumbar spine, and to discuss problems that have occurred among youth.
Subjects and methods Key words Lumbar spine · Lordosis · Youth
Introduction The muscles and ligaments around the lumbar spine may influence posture. Such postural changes can be a source of low back pain. Although there are several reports discussing the relation between low back pain and lumbar spinal alignment,1–11,13,14 there are no reports on postural changes in the younger generation in Japan. The physical constitution of youth has reportedly changed during the past 10 years.12 Height and weight have increased as compared with previous findings. In contrast, muscle strength, such as that of the back muscles, is reported to be weaker than it was 10 years ago. These changes, and the consequent imbalance, may cause changes in spinal alignment.
Offprint requests to: Y. Murata, Linnégatan 45, Apartment nr: 107 SE-413 08 Gothenburg, Sweden Received: March 25, 2002 / Accepted: June 12, 2002
Three hundred and thirty-six Japanese youth (198 men and 138 women), whose ages ranged from 12 to 20 years, were included in this study. The subjects were composed of four groups: group Am, 85 young men (mean age, 16.2 ⫾ 2.2 years) who had low back pain and underwent radiographic examination of the lumbar spine in a standing position during the period from 1985 to 1988; group Af, 62 young women (mean age, 16.2 ⫾ 2.4 years) from 1985 to 1988; group Bm, 113 young men (mean age, 15.8 ⫾ 2.1 years) from January 1999 to June 1999; and Group Bf, 76 young women (mean age, 15.9 ⫾ 2.1 years) from January 1999 to June 1999. The exclusion criteria of the subjects were scoliosis, kyphosis, spondylolysis, and spondylolisthesis. In addition, we graded the symptoms, with 15 points representing full marks, using parts I and II of the Japanese Orthopaedic Association (JOA) score. Subjects were limited to those with rather minor pain that could be treated without spinal surgery. To obtain accurate lateral radiographs of the lumbar spine, the patient’s knees were extended as much as possible, the hips were aligned perpendicular to the film, the legs and feet positioned close together, and the arms were held out straight and supported by
Y. Murata et al.: Lumbar lordosis in youth
gripping a bar, in accordance with previous studies.6–10,12 Each lateral radiograph was independently measured by two observers, using Cobb’s method.1–11,13,14 Lumbar lordosis was measured as the angle between the superior endplate of L1 and the superior endplate of S1; sacral inclination was measured as the angle between the superior endplate of S1 and a horizontal line. We also measured the angles in randomly selected members of an other generation, with the subjects being 129 adults (56 men and 73 women, mean age, 53.1 ⫾ 11.4 years; range, 21–79 years) who underwent radiographic examination with the same procedure during the period from 1985 through 1988 (groups Cm and Cf), and 126 adults (63 men and 63 women; mean age, 57.2 ⫾ 13.5 years; range, 21–79 years) during the period from 1998 through June 1999 (groups Dm and Df). The adult subjects were also limited to those with rather minor pain which could be treated without spinal surgery. Statistical analysis was performed using Student’s t-test. All probability values were calculated within a confidence interval of 95%.
Results Intraobserver variance ranged from 0° to 5.0° with an average of 1.7° (95% confidence limit, ⫾1.5°), and interobserver variance ranged from 0° to 9.0°, with an average of 2.6° (95% confidence limit, ⫾2.3°). The average JOA score was 11.8 ⫾ 2.0 in group Am, 12.1 ⫾ 1.6 in Af, 11.7 ⫾ 2.1 in Bm, and 12.0 ⫾ 1.9 in Bf. The
619
average JOA score was 11.0 ⫾ 2.4 in group Cm, 11.5 ⫾ 2.3 in Cf, 10.8 ⫾ 2.4 in Dm, and 11.3 ⫾ 2.4 in Df. There were no statistically significant differences among them (15 points full marks). Mean values for the measurements in each group are shown in Fig. 1. Both the lordotic angle and sacral inclination were significantly larger in group Bm than in Am (P ⬍ 0.0001), and in Bf they were also significantly larger than in Af (P ⬍ 0.0001). However, there was no significant difference between Cm and Dm, or between Cf and Df. With regard to sex, regarding the lordotic angle, there was no significant difference between Am and Af, Cm and Cf, or Dm and Df, although the angle in Bm was significantly larger than that in Bf (P ⬍ 0.01). The mean values in each age group are shown in Fig. 2. Both the mean lordotic angle and sacral inclination were significantly larger in Bm than in Am at ages 13 to 19 years (P ⬍ 0.05).
Discussion Many authors have paid attention to the relation between lumbar lordosis and low back pain in their reports. It is suggested that the loss of lordosis in the lumbar spine is associated with low back pain.6,7,10,12,13 Some authors stated that, in a position in which the lordosis decreases, intradiscal pressure will consequently increase, and the increased intradiscal pressure may become the underlying factor for the low back pain.1,9 However, the relation between the degree of low
b
a Fig. 1. a Each bar shows the mean lordotic angle. The angle was significantly larger in group Bm than in Am (P ⬍ 0.0001), and was also significantly larger in Bf than in Af (P ⬍ 0.0001). However, there was no significant difference among Cm, Cf, Dm, and Df. With regard to sex, there was no significant difference between Am and Af, although the angle in Bm was significantly larger than in Bf (P ⬍ 0.01). There was no significant difference in lordotic angle among groups Am, Af, Cm, Cf, Dm, and Df. b Each bar shows the mean sacral inclination. The angle was significantly larger in group Bm than in Am (P ⬍ 0.0001), and was also significantly larger in Bf than
in Af (P ⬍ 0.0001). However, there was no significant difference among Cm, Cf, Dm, and Df. Group Am, Eighty-five young men with low back pain who underwent radiographic examination of the lumbar spine during the period from 1985 to 1988; group Af, 62 young women from 1985 to 1988; group Bm, 113 young men from January 1999 to June 1999; group Bf, 76 young women from January 1999 to June 1999; group Cm, 56 adult men from 1985 through 1988; group Cf, 73 adult women from 1985 through 1988; group Dm, 63 adult women from 1998 through June 1999; group Df, 63 adult men from 1998 through June, 1999
620
a
Y. Murata et al.: Lumbar lordosis in youth
b
Fig. 2. a The mean lordotic angles in each age group are shown. The mean lordotic angle was significantly larger in group Bm (today) than in Am (10 years ago) at ages 13 to 19 years (P ⬍ 0.05). b The mean sacral inclinations in each age group are shown. The mean angle was significantly larger in group Bm than in Am at ages 13 to 19 years (P ⬍ 0.05)
Fig. 3. Each bar shows the mean height of men and women in 1985 (white bars), 1990 (diagonally striped bars), 1995 (vertically striped bars), and 1998 (black bars), at ages 12 to 17 years. The graphs clearly show that the values are gradually increasing in each age group. The data are quoted from a 1999 government publication12
Fig. 4. Each bar shows the mean back muscle strength of men and women in 1985 (white bars), 1995 (diagonally striped bars), and 1997 (black bars) at ages 12 to 17 years. They indicate that the values are gradually decreasing in each age group. The data are quoted from a 1999 government publication12
back pain and sagittal lumbar alignment have not been examined. Likewise, although the present study clarified the postural changes of patients with low back pain, we failed to consider the degree of low back pain. Long follow-up studies on an asymptomatic population are yet to be conducted for further classification. The living environment and lifestyles are rapidly changing in Japan. These changes may lead to changes in physique and muscle strength.9 According to a 1999 government publication,12 the mean height of Japanese youth has increased for the past 13 years (Fig. 3). The
mean weight has also increased during the same period. Conversely, back muscle strength has decreased for the past 12 years (Fig. 4). The range of trunk extension has also become more limited (Fig. 5). The data indicate that muscle strength around the lumbar spine has become weaker than before. This change can be a factor influencing alignment of the lumbar spine. Furthermore, the range of standing trunk flexion, which reflects the flexibility of the trunk, has become more limited (Fig. 6). Both trunk extension and standing trunk flexion have a relation to lumbar spine motion.
Y. Murata et al.: Lumbar lordosis in youth
621
Fig. 5. Each bar shows the mean value of trunk extension (ext.) of men and women in 1985, 1995, and 1997 at ages 12 to 17 years. Bars, As in Fig. 4. The values show a tendency to decrease in each age group. The data are quoted from a 1999 government publication12
Fig. 6. Each bar shows the mean value of standing trunk flexion ( flex.) of men and women in 1985, 1995, and 1997 at ages 12 to 17 years. Bars, As in Fig. 4. The values have a tendency to decrease in each age group. The data are quoted from a 1999 government publication12
Regarding Japanese youth today, we can say that their physique is larger, the muscle around the lumbar spine is weaker, and the pliability of the lumbar spine has decreased. It is reasonable to consider that changes in balance will influence the posture. Although the present study clarified the postural changes of patients with low back pain, these quoted data on physique and muscle strength are those of an asymptomatic population. We failed to consider the height, weight, and muscle strength of our subjects. Long follow-up investigations on an asymptomatic population are yet to be conducted for further studies. In the present study, the change was shown as an increase in lumbar lordotic angle and sacral inclination. These may be aspects of postural changes among youth people. Changes in physique, muscle strength, pliability, and posture may be affected by lifestyle. Multiple factors, including activity, eating habits, and living environment, may be cited as causes of the changes. For example, as regards the activity of young people, students are
obliged to study hard from earlier ages than before, in order to get into higher level schools, because Japanese society tends to attach importance to one’s academic career. This social phenomenon is probably related to the lack of exercise among youth. Another related factor may be the development of transport facilities. The popularization of personally owned cars is also a probable cause of lack of exercise. Moreover, children used to play outside in the past. However, since computer games began to be sold about 20 years ago, and as the computer games propagated, the youth tended to play alone in a room, and not to play with friends outdoors. These factors may influence muscle strength among youth. The weakness of the muscles around the lumbar spine may be a cause of low back pain. These are probably only a few of the multiple factors that can influence young people. What is important in the treatment of low back pain among youth today may be to improve their lifestyles. We should carefully consider pathophysiology when we treat low back pain in young patients.
622
Y. Murata et al.: Lumbar lordosis in youth
References 1. Adams MA, Hutton WC. The effect of posture on the lumbar spine. J Bone Joint Surg Br 1985;67:625–9. 2. Bernhardt M, Bridwell KH. Segmental analysis of the sagittal plane alignment of the normal thoracic and lumbar spines and thoracolumbar junction. Spine 1989;14:717–21. 3. Chernukha KV, Daffner RH, Reigel DH. Lumbar lordosis measurement: a new method versus Cobb technique. Spine 1998;23:74– 80. 4. Gelb DE, Lenke LG, Bridwell KH, et al. An analysis of sagittal spinal alignment in 100 asymptomatic middle and older aged volunteers. Spine 1995;20:1351–8. 5. Hasday CA, Passoff TL, Perry J. Gait abnormalities arising from iatrogenic loss of lumbar lordosis secondary to Harrington instrumentation in lumbar fractures. Spine 1983;8:501–11. 6. Jackson RP, McManus AC. Radiographic analysis of sagittal plane alignment and balance in standing volunteers and patients with low back pain matched for age, sex, and size. A prospective controlled clinical study. Spine 1994;19:1611–8. 7. Jackson RP, Peterson MD, McManus AC, et al. Compensatory spinopelvic balance over the hip axis and better reliability in
8.
9.
10. 11.
12.
13.
14.
measuring lordosis to the pelvic radius on standing lateral radiographs of adult volunteers and patients. Spine 1998;23:1750– 67. Korovessis PG, Stamatakis MV, Baikousis AG. Reciprocal angulation of vertebral bodies in the sagittal plane in an asymptomatic Greek population. Spine 1998;23:700–5. Lee CS, Lee CK, Kim YT, et al. Dynamic sagittal imbalance of the spine in degenerative flat back. Significance of pelvic tilt in surgical treatment. Spine 2001;26:2029–35. Lord MJ, Small JM, Dinsay JM, et al. Lumbar lordosis. Effects of sitting and standing. Spine 1997;22:2571–4. Stagnara P, De Mauroy JC, Dran G, et al. Reciprocal angulation of vertebral bodies in a sagittal plane. Approach to references for the evaluation of kyphosis and lordosis. Spine 1982;7:335–42. Taka T. Statistical abstract of education, science, sports and culture. Tokyo: Printing Bureau, Ministry of Education, Science, Sports and Culture; 1999. p. 132–9. Vedantam R, Lenke LG, Keeney JA, et al. Comparison of standing sagittal spinal alignment in asymptomatic adolescents and adults. Spine 1998;23:211–5. Williams MM, Hawley JA, McKenzie RA, et al. A comparison of the effects of two sitting postures on back and referred pain. Spine 1991;16:1185–91.