Comparison of hip rotation range of motion in judo athletes with and without history of low back pain

Comparison of hip rotation range of motion in judo athletes with and without history of low back pain

Manual Therapy 17 (2012) 231e235 Contents lists available at SciVerse ScienceDirect Manual Therapy journal homepage: www.elsevier.com/math Original...

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Manual Therapy 17 (2012) 231e235

Contents lists available at SciVerse ScienceDirect

Manual Therapy journal homepage: www.elsevier.com/math

Original article

Comparison of hip rotation range of motion in judo athletes with and without history of low back pain Gabriel Peixoto Leão Almeida a, *, Vivian Lima de Souza a, Saulo Sadao Sano a, Michele Forgiarini Saccol b, c, Moisés Cohen a a

Centro de Traumatologia do Esporte (CETE), Departamento de Ortopedia e Traumatologia, Universidade Federal de São Paulo, Escola Paulista de Medicina, São Paulo, SP, Brazil1 Departamento de Fisioterapia da Universidade Federal de São Carlos (SP), Brazil c Universidade Federal do Pampa, Uruguaiana, RS, Brazil

b

a r t i c l e i n f o

a b s t r a c t

Article history: Received 3 July 2011 Received in revised form 22 December 2011 Accepted 7 January 2012

This study compared hip rotation range of motion in judo athletes with and without a history of low back pain. Forty-two athletes (22 males) were divided into two groups: 21 with history of low back pain (HLBP) and 21 without history of low back pain (Control). Internal and external hip rotation range of motion in active and passive movement were measured using computed photogrammetry. The HLBP group exhibited a significant reduction in active internal rotation (27.5  6.5 vs 38.2  6.5 ), active total rotation (80.1  9.5 vs 87.4  7.9 ) of the non-dominant limb (P < 0.01) and active total rotation (82.6  7.6 vs 87.6  9.8 ; P ¼ 0.04) in comparison with the control group. In passive rotation, the HLBP group showed a significant reduction in internal rotation of the dominant (41.9  6.1 vs 46.1  8.4 ; P ¼ 0.04) and non-dominant limb (37.1  8.4 vs 47.3  7.6 ; P < 0.001), total rotation of the nondominant limb (96.7  10.2 vs 105.1  11 ; P ¼ 0.005) and total rotation (98.5  9.2 vs 105  11.2 ; P ¼ 0.02). Within the HLBP group, a significant reduction in both active and passive internal rotation (P < 0.001) and active and passive total rotation (P < 0.01) of the non-dominant limb was detected. The same was not found in the control group. The results demonstrate that judo athletes with a history of low back pain exhibit deficits in hip rotation and greater asymmetry between limbs. Ó 2012 Elsevier Ltd. All rights reserved.

Keywords: Hip rotation Judo Low back pain Range of motion

1. Introduction Athletes often recruit or transfer high levels of force through the back in a repetitive fashion, which is an important aspect in the increase of episodes of low back pain in this population (Lundin et al., 2001; Ong et al., 2003). The prevalence of low back pain in athletes ranges from 30 to 85% (Ganzit et al., 1998; Lundin et al., 2001; Iwai et al., 2004) and this condition is estimated to account for 10e15% of all sport-related injuries (Graw and Wiesel, 2008). Similar findings are reported for practitioners of judo, as studies report a 35e62% prevalence of non-specific low back pain in this population (Yamaji et al., 1992; Okada et al., 2007).

* Corresponding author. Rua Botelho, n 245, Vila Guarani; Cep: 04313-200; São Paulo, SP, Brazil. Tel.: þ55 11 87708321, þ55 11 55395090; fax: þ55 11 55395090. E-mail address: [email protected] (G.P.L. Almeida). 1 Name and address of department: Centro de Traumatologia do Esporte (CETE), Departamento de Ortopedia e Traumatologia da Universidade Federal de São Paulo, Rua Estado de Israel, n 638B, Vila Clementino; Cep: 04022-002; São Paulo, SP, Brazil. 1356-689X/$ e see front matter Ó 2012 Elsevier Ltd. All rights reserved. doi:10.1016/j.math.2012.01.004

A history of low back pain is the main predictor of future occurrences, as athletes with a previous episode of this condition have a threefold greater chance of experiencing a further episode (Nachemson, 1992; Greene et al., 2001). Another worrisome factor is that approximately 85% of cases of low back pain do not receive a specific diagnosis associated to the symptoms of the patient (Graw and Wiesel, 2008). Therefore, despite the high incidence of this condition, the etiology of chronic low back pain is not fully understood, which makes diagnosis and treatment a challenge for health professionals who work with athletes (Bono, 2004; Carlson, 2009). Knowledge regarding factors that may contribute toward the development of low back pain could facilitate the establishment of more effective prevention measures and treatment (Harris-Hayes et al., 2009). Due to the anatomic proximity and muscle connections, a number of studies have investigated the relationship between hip mobility and episodes of low back pain (Ellison et al., 1990; Cibulka et al., 1998; Vad et al., 2004; Van Dillen et al., 2008; Murray et al., 2009). It is theorized that limited hip range of motion is compensated by hypermobility of the lumbar region, generating overload with repetitive compensatory movements (Van Dillen et al., 2007, 2008).

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While some studies report such an association, it has yet to be firmly established. Divergences between studies are related to the lack of standardization in the classification of low back pain as well as variations in the frequency, intensity and volume of training sessions. Moreover, previous studies have failed to take into account the need for hip rotation in sport activities (Van Dillen et al., 2008; Harris-Hayes et al., 2009). In their attempt to standardize the repercussion of the deficit in hip rotation in cases of low back pain, Vad et al. (2003) were the first researchers to study this relationship in tennis players and later analyzed this same aspect in practitioners of golf (Vad et al., 2004). However, there remains a lack of studies relating low back pain to specific sports that involve repetitive rotation of the hip. The aim of the present study was to compare hip rotation range of motion in judo athletes with and without a history of low back pain, as this sport requires abrupt rotation movements of the hips and lumbopelvic region in order to obtain leverage and destabilize the opponent. The hypothesis was that judo athletes with history of low back pain present imbalance in the hip rotation range of motion. 2. Methods 2.1. Subjects A cross-sectional case-control study was carried out involving 42 participants (22 males and 20 females) between 15 and 23 years of age. All participants or their parents/guardians signed an informed consent form agreeing to participate. This study received approval from the Human Research Ethics Committee of the Federal University of São Paulo (Brazil). The following were the inclusion criteria: a minimum of four years experience practicing judo; belonging to an official judo club/ league; practice routine of a minimum of two hours per day three days per week; and 1) a history of low back pain in the past 12 months (HLBP group) or 2) never having a history of low back pain (Control group). It was determined that low back pain must have lasted for at least two weeks in order to exclude simpler cases that lasted only a few days (Vad et al., 2004). Individuals with a history of low back pain due to the following reasons were excluded: prior back surgery; diagnosed kyphosis or scoliosis; spinal stenosis; fracture; degenerative disk disease; herniated disk; serious spinal conditions, such as tumor or infection; and hip or knee injury. Individuals with muscle injury in the lower limbs in the previous three months or previous hip/knee injury or surgery were also excluded. Based on the eligibility criteria, 13 of the initial sample of 55 athletes were excluded from the study, totalizing in the end 11 men and 10 women in each group.

camera (FUJIFILMÒ Finepix 5.0 Megapixels) was positioned on a tripod at a distance of 2 m from the examining table, with a plumb line positioned behind the table for the vertical reference. The participants were placed in the prone position on a standard examining table. The limb being evaluated was placed with the hip in neutral position on the frontal and sagittal planes, 90 flexion of the knee with universal goniometer and the ankle in resting position. During the assessment of internal rotation, the contralateral limb remained in neutral position on the frontal and sagittal planes. During the assessment of external rotation, the contralateral limb was placed in neutral position on the sagittal plane, with 20 abduction on the frontal plane. The examiner manually stabilized the athlete’s pelvis in order to minimize compensations during active and passive rotation of the hip. Upon receiving the command to begin the rotation movement, the subject performed active movement of the limb until reaching the maximal limit. Maintaining the same position, maximal passive rotation range of motion was then performed. The movement were also performed in the opposite direction and then on the contralateral limb. The final amplitude was measured from the combination of the manual perception of the end feel and observation of compensations, and digital picture was taken at the end of the rotation. The examiners were blinded to the group to which the participants belonged, with one examiner in charge of hip stabilization and test execution (G.P.L.A.) and another in charge of taken digital picture (V.L.S.). The rotation movement and limb to be examined first were randomized by lots, with pieces of paper containing the words “external rotation”, “internal rotation”, “right” and “left”. For the determination of the dominant lower limb, each participant was asked the following question: “Imagining a ball in front of you, what leg would you use to kick it in order to achieve the greatest possible force?” (Hoffman et al., 1998). The digital image was used to determine the active and passive hip rotation range of motion range of motion, using the Postural Assessment Software v.0.67 (PAS/SAPO) (Ferreira et al., 2010). From these data, the total rotation range of motion of each limb (sum of medial and lateral rotation) and total rotation of each individual (sum of total rotation of dominant and non-dominant limb divided by 2) were also calculated. 2.4. Data analysis

Each participant answered a questionnaire addressing anthropometric characteristics, competitive level, episodes of low back pain in the previous 12 months, characteristics of low back pain and a visual analog pain scale. The Roland-Morris questionnaire was employed to assess subjective functional capacity of the lumbar region (Nusbaum et al., 2001). Based on the results of the questionnaire, the participants were divided into two groups: HLBP group and Control group.

Intra-examiner and inter-examiner reliability was determined prior to the data collection. For such, 10 healthy subjects with no previous history of low back pain were submitted to both passive and active medial and lateral hip rotation range of motion by two blinded examiners with a one-week interval between the first and second evaluation. The Intraclass Correlation Coefficient (ICC) and standard error values were calculated for all measures. The KolmogoroveSmirnov test was used to determine the normality of the data. Descriptive statistics and either the Student’s t-test or chi-square test were used to identify differences between the two groups. The Student’s t-test for independent samples was used to determine differences in hip rotation between groups. The Student’s t-test for paired samples was used to determine differences in rotation between the dominant and non-dominant limb within each group. The level of significance was set at 5% (P  0.05). The Statistical Package for the Social Sciences (SPSS 17.0 for Windows, Chicago, IL, USA) was used for the statistical calculations.

2.3. Laboratory measures

3. Results

For the assessment of hip rotation range of motion, two reflectors were placed over the anterior tuberosity of the tibia and in the central region between the medial and lateral malleolus. A digital

There were no statistically significant differences between groups with regard to age, weight, height, body mass index, gender, training experience, weekly training frequency or hours of training

2.2. Clinical measures

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Table 1 Differences (mean  standard deviation) in characteristics of judo practitioners with low back pain (HLBP) and those without low back pain (control group). HLBP group (N ¼ 21) Age  SD (years) Weight  SD (Kg) Height  SD (m) BMI  SD (Kg/m2) Training experience  SD (years) Weekly practice frequency  SD Hours of practice per day  SD Hours of practice per week  SD

16.7 60.1 1.64 22.1 8.9 5 2.1 10.1

       

2.9 11.3 .1 2.8 2.9 0.8 0.4 1.3

per day and per week (Table 1). The characteristics of the HLBP group are displayed in Table 2. 3.1. Reliability Excellent intra-examiner and inter-examiner reliability were demonstrated for the hip rotation measurements using computed photogrammetry. The ICC for the measures of active medial and lateral hip rotation ranged from 0.93 to 0.97. For passive internal and external hip rotation, the ICC ranged from 0.86 to 0.96, respectively (Table 3). 3.2. Inter-group comparisons The HLBP group demonstrated significantly less active internal rotation of the non-dominant limb (HLBP: 27.5  6.5 , Control: 38.2  6.5 , 95% CI ¼ 14.2 to 7.2) (Fig. 1), active total rotation of the non-dominant limb (HLBP: 80.1  9.5 , Control: 87.4  7.9 , 95% CI ¼ 11.8 to 2.7) and active total rotation (HLBP: 82.6  7.6 , Control: 87.6  9.8 , 95% CI ¼ 9.8 to 0.07) than the control group (Fig. 3). No significant differences between groups were detected with regard to active internal rotation of the dominant limb (HLBP: 34.1  6.4 , Control: 37.9  9.7, 95% CI ¼ 8.5 to 0.8) (Fig. 1), active external rotation of the dominant and non-dominant limbs (HLBP: 51  6.5 , Control: 50.1  9.9 , 95% CI ¼ 3.6 to 5.5; and HLBP: 51.3  6.4 , Control: 49.2  7.6 , 95% CI ¼ 1.7 to 6.02, respectively) (Fig. 2) and total active rotation of the dominant limb (HLBP: 85.1  6.9 , Control: 87.9  12.6 , 95% CI ¼ 8.7 to 3.1) (Fig. 3). With regard to passive hip rotation, significant difference between groups were detected for internal rotation of the dominant and non-dominant limb (HLBP: 41.9  6.1, Control: 46.1  8.4 , 95% CI ¼ 8.3 to 0.08; and HLBP: 37.1  8.4 , Control: 47.3  7.6 , 95% CI ¼ 14.4 to 6.01, respectively) (Fig. 1), total rotation of the non-dominant limb (HLBP: 96.7  10.2 , Control: 105.1  11, 95% CI ¼ 14.1 to 2.6), and total rotation (HLBP: 98.5  9.2 , Control: 105  11.2 , 95% CI ¼ 12.2 to 0.8) (Fig. 3). No significant differences between groups were detected with regard to passive external rotation of the dominant and non-dominant

Table 2 Characteristics of group with low back pain. Variable

Value

Mean number of years with low back pain  SD (min. and max.) Mean number of episodes of low back pain in previous 12 months  SD Number of participants which training or competitions missed due to low back pain Number of participants with irradiating pain associated with low back pain Mean score on visual analog pain scale  SD (0e10) Mean score on Roland-Morris scale  SD (0e24)

1.2  0.5 (1e3) 4.8  8.3

Control group (N ¼ 21) 16.3 61.5 1.65 22.5 8.4 4.8 2.1 10.5

       

4.1  2.6 3.8  2.7

t t t t t t t t

¼ ¼ ¼ ¼ ¼ ¼ ¼ ¼

0.606, P ¼ 0.55 0.513, P ¼ 0.61 0.352, P ¼ 0.72 0.506, P ¼ 0.61 0.616, P ¼ 0.54 0.259, P ¼ 0.79 0.387, P ¼ 0.70 0.512, P ¼ 0.60

limb (HLBP: 58.4  5.6 , Control: 58.9  10.8 , 95% CI ¼ 6.02 to 5.03; and HLBP: 59.7  5.8 , Control: 57.8  10.8 , 95% CI ¼ 3.2 to 6.9, respectively) (Fig. 2) and passive total rotation of the dominant limb (HLBP: 100.3  8.9 , Control: 105  12.1, 95% CI ¼ 10.7 to 1.2) (Fig. 3). 3.3. Intra-group comparisons In the HLBP group, significant reduction of the non-dominant limb compared dominant limb were detected regard to active internal rotation (Difference: 6.6  5.3 , 95% CI ¼ 4.1e9.03, P < 0.001), passive internal rotation (Difference: 4.8  4 , 95% CI ¼ 2.9e6.7, P < 0.001), active total rotation (Difference: 4.9  6.8 , 95% CI ¼ 1.8e8.08, P ¼ 0.003) and passive total rotation (Difference: 3.5  5.2 , 95% CI ¼ 1.1e5.9, P ¼ 0.005). No significant differences were found with regard to active external rotation and passive external rotation of the limbs (Difference: 0.3  6.1, 95% CI ¼ 3.09 to 2.5, P ¼ 0.82; and Difference: 1.3  6 , 95% CI ¼ 4.05 to 1.4, P ¼ 0.33, respectively). In the control group, no significant differences between limbs were detected with regard to active internal and external rotation (Difference: 0.3  6.7, 95% CI ¼ 2.4 to 1.7, P ¼ 0.75; and Difference: 0.8  5.1, 95% CI ¼ 0.7 to 2.4, P ¼ 0.27, respectively), passive internal and external rotation (Difference: 1.1  5.4 , 95% CI ¼ 2.8 to 0.5, P ¼ 0.17; and Difference: 1  4.5 , 95% CI ¼ 0.3 to 2.4, P ¼ 0.14, respectively) and active and passive total rotation of the limbs (Difference: 0.5  7.8 , 95% CI ¼ 1.9 to 2.9, P ¼ 0.67; and Difference: 0.1  5.9 , 95% CI ¼ 1.9 to 1.7, P ¼ 0.89, respectively). 4. Discussion The purpose of the present study was to compare hip rotation range of motion between practitioners of judo with and without a history of low back pain. The results reveal that those with a history of non-specific low back pain exhibited a significant reduction in active and passive hip range of motion in comparison with no history of low back pain athletes. Moreover, within the HLBP group, a significant reduction was found in active and passive internal rotation, and active and passive total rotation of the nondominant limb in comparison to the dominant limb, whereas no significant differences between limbs were found in the control group. Similar studies have been carried out on sedentary

Table 3 Intraclass correlation coefficient for intra-examiner and inter-examiner measurements using computed photogrammetry.

6 athletes 3 athletes

Statistical and probability values

2 9.9 0.1 3.2 3.1 0.7 0.5 2.8

Active medial rotation Active lateral rotation Passive medial rotation Passive lateral rotation

Intra-examiner reliability (3.1)

Inter-examiner reliability (3.2)

0.96 0.97 0.93 0.96

0.97 0.93 0.86 0.93

(95% (95% (95% (95%

CI CI CI CI

0.92e0.98) 0.93e0.98) 0.84e0.96) 0.93e0.98)

(95% (95% (95% (95%

CI CI CI CI

0.93e0.98) 0.86e0.97) 0.73e0.93) 0.86e0.96)

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Fig. 1. Low back pain group (HLBP) versus control group (control) differences in active and passive internal rotation of the dominant and non-dominant limb. *Significant difference (P < 0.05) between groups. ***Significant difference (P < 0.001) between groups.

individuals (Ellison et al., 1990; Cibulka et al., 1998) and practitioners of physical activities with low back pain, such as golf (Vad et al., 2004; Murray et al., 2009), tennis (Vad et al., 2003) and other sports that require repetitive hip rotation movements (Van Dillen et al., 2008; Harris-Hayes et al., 2009; Scholtes et al., 2009). However, to the knowledge of the authors of the present investigation, there are no previous studies in the literature on hip rotation among judo athletes. There seems to be an association between hip rotation range of motion and a history of low back pain, but this relationship is not yet well defined in the literature (Vad et al., 2003, 2004; Van Dillen et al., 2008; Murray et al., 2009; Scholtes et al., 2009). According to HarrisHayes et al. (2009), studies on this topic should take care to make the groups homogeneous in order to clarify this association better. For such, factors such as physical activity, gender and classification of low back pain should be taken into account. In compliance with these recommendations, the present study evaluated practitioners of league judo with no specific injury related to low back pain (exclusion criterion) and there were no significant differences between groups with regard to gender, experience with judo, weekly training frequency or hours of practice per week and per day. A number of studies have focused on the association between hip rotation range of motion and low back pain (Ellison et al., 1990; Cibulka et al., 1998; Vad et al., 2004; Van Dillen et al., 2008; Murray et al., 2009). However, few papers have considered this association in athletes who practice sports that require repetitive hip rotation movements. It is suggested that athletes who use repetitive hip rotation when practicing sports and those who need the total range of motion of the hip are more prone to back pain (Harris-Hayes et al., 2009). Van Dillen et al. (2008) found a significant reduction in total hip rotation as well as greater asymmetry in total rotation between the limbs among those with a history of low back pain. Harris-Hayes et al. (2009) found a difference in total rotation between the group with low back pain and the control group in practitioners of different sports. The authors also demonstrated a difference in total rotation between the limbs in the group with low back pain, whereas this difference was not detected in the control group. Murray et al. (2009) found a reduction in total passive rotation and active internal rotation in the dominant limb in relation to the control group. Vad et al. (2004) report a significant reduction in rotation in the dominant hip (Fabere’s distance) in golfers with low back pain in comparison to the control group. Similar findings are reported for professional tennis players, as those with low back

Fig. 2. Low back pain group (HLBP) versus control group (control) differences in active and passive external rotation of the dominant and non-dominant limb. No significant difference was found.

pain exhibited a significant reduction in internal hip rotation of the dominant limb in comparison to the control group (Vad et al., 2003). Although none of the aforementioned studies were carried out with practitioners of judo or similar martial art, the findings are in agreement with the results of the present investigation, in which the athletes with low back pain exhibited a significant reduction in hip rotation and greater asymmetry in range of motion between limbs in comparison to the asymptomatic control group. Besides the possible increased load on lumbopelvic structures to counteract the diminished hip rotation, a number of authors report a premature movement and greater lumbopelvic rotation range of motion during hip rotation in individuals with low back pain in comparison to asymptomatic individuals, indicating possible compensatory movement (Van Dillen et al., 2007; Scholtes et al., 2009, 2010; Van Dillen et al., 2009; Hoffman et al., in press). The results of the present study are relevant to the current literature, as the findings suggest that practitioners of judo with a history of low back pain may exhibit a significant reduction in hip rotation and greater asymmetry between limbs in comparison to practitioners without low back pain. It is possible that differences in mobility have contributed to the development of LBP, but another explanation could be that because of LBP the patients move differently causing adaptations at the hip level. Thus, clinical trials are requires to identify efficacy of interventions aimed specific techniques for increasing flexibility and hip range of motion, stabilization exercises and lumbopelvic control in order to minimize and/or prevent pain symptoms in the lower back.

Fig. 3. Low back pain group (HLBP) versus control group (control) differences in active and passive total rotation of the dominant and non-dominant limb, and total rotation. *Significant difference (P < 0.05) between groups. **Significant difference (P < 0.01) between groups.

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Further studies are needed to clarify the association found in the present study. As the participants were young athletes, future studies should determine whether the findings described here are repeated in older practitioners of judo. Current data cannot define whether differences in ROM are from nature/nurture, adaptive/ maladaptive, cause/effect/unrelated to LBP. We suggest the need for further study of the causality and clinical trials for interventions to affect the incidence/recurrence of LBP. Three-dimensional analysis of the movements of the hips and lumbopelvic region could clarify an association between possible biomechanical flaws and a reduction in hip rotation in practitioners of judo. Moreover, assessments should be performed to determine whether an early lumbopelvic movement and greater range of motion actually occur in practitioners of this sport. It is worth recognizing that aside from hip rotation in prone, other hip active/passive ranges of motion (such as rotations in sitting, hip flexion and extension) could also influence lumbar motion and load in functional tasks. Others studies can determine differences possible between measures tests for hip range of motion. 5. Conclusion The results of the present study demonstrate that practitioners of judo with a history of low back pain exhibit a significant reduction in active medial rotation and total active rotation of the hip in the non-dominant limb in comparison to asymptomatic practitioners of the sport. Moreover, significant asymmetry between limbs was found with regard to active and passive internal rotation in the group with low back pain, which did not occur in the group without low back pain. These results underscore the importance of assessing hip rotation in practitioners of judo prior to planning prevention measures and therapy for low back pain. References Bono CM. Low-back pain in athletes. The Journal of Bone and Joint and Joint Surgery 2004;86-A(2):382e96. Carlson C. Axial pain in the athlete: pathophysiology and approach to rehabilitation. Current Reviews in Musculoskeletal Medicine 2009;2(2):88e93. Cibulka MT, Sinacore DR, Cromer GS, Delitto A. Unilateral hip rotation range of motion asymmetry in patients with sacroiliac joint regional pain. Spine (Phila Pa 1976) 1998;23(9):1009e15. Ellison JB, Rose SJ, Sahrmann SA. Patterns of hip rotation range of motion: a comparison between healthy subjects and patients with low back pain. Physical Therapy 1990;70(9):537e41. Ferreira EAG, Duarte M, Maldonado EP, Burke TN, Marques AP. Postural assessment software (PAS/SAPO): validation and reliability. Clinics 2010;65(7):675e81. Ganzit GP, Chisotti L, Albertini G, Martore M, Gribaudo CG. Isokinetic testing of flexor and extensor muscles in athletes suffering from low back pain. Journal of Sports Medicine and Physical Fitness 1998;38(4):330e6.

235

Graw BP, Wiesel SW. Low back pain in the aging athlete. Sports Medicine and Arthroscopy Review 2008;16(1):39e46. Greene HS, Cholewick J, Galloway MT, Nguyen CV, Radebold A. A history of low back injury is a risk factor for recurrent back injuries in varsity athletes. American Journal of Sports Medicine 2001;29(6):795e800. Harris-Hayes M, Sahrmann SA, Van Dillen LR. Relationship between the hip and low back in athletes who participate in rotation-related sports. Journal of Sport Rehabilitation 2009;18(1):60e75. Hoffman M, Schrader J, Applegate T, Koceja D. Unilateral postural control of the functionally dominant and nondominant extremities of healthy. Journal of Athletic Training 1998;33(4):319e22. Hoffman SL, Johnson MB, Zou D, Harris-Hayes M, Van Dillen LR. Effect of classification-specific treatment on lumbopelvic motion during hip rotation in people with low back pain. Manual Therapy 2011;16(4):344e50. Iwai K, Nakazato K, Irie K, Fujimoto H, Nakajima H. Trunk muscle strength and disability level of low back pain in collegiate wrestlers. Medicine & Science in Sports & Exercise 2004;36(8):1296e300. Lundin O, Hellstrom M, Nilsson I, Sward L. Back pain and radiological changes in the thoraco-lumbar spine of athletes. A long-term follow-up. Scandinavian Journal of Medicine & Science in Sports 2001;11(2):103e9. Murray E, Birley E, Twycross-Lewis R, Morrissey D. The relationship between hip rotation range of movement and low back pain prevalence in amateur golfers: an observational study. Physical Therapy in Sport 2009;10(4):131e5. Nachemson AL. Newest knowledge of low back pain. A critical look. Clinical Orthopaedics and Related Research 1992;279:8e20. Nusbaum L, Natour J, Ferraz MB, Goldenberg J. Translation, adaptation and validation of the Roland-Morris questionnaireeBrazil Roland-Morris. Brazilian Journal of Medical and Biological Research 2001;34:203e10. Ong A, Anderson J, Roche J. A pilot study of the prevalence of lumbar disc degeneration in elite athletes with lower back pain at the Sydney 2000 Olympic Games. British Journal of Sports Medicine 2003;37(3):263e6. Okada T, Nakazato K, Iwai K, Tanabe M, Irie K, Nakajima H. Body mass, nonspecific low back pain, and anatomical changes in the lumbar spine in judo athletes. Journal of Orthopaedic and Sports Physical Therapy 2007; 37(11):688e93. Scholtes SA, Gombatto SP, Van Dillen LR. Differences in lumbopelvic motion between people with and people without low back pain during two lower limb movements tests. Clinical Biomechanics (Bristol, Avon) 2009;24(1): 7e12. Scholtes SA, Norton BJ, Lang CE, Van Dillen LR. The effect of within-session instruction on lumbopelvic motion during a lower limb movement in people with and people without low back pain. Manual Therapy 2010;15(5): 496e501. Vad VB, Bhat AL, Basrai D, Gebeh A, Aspergren DD, Andrews JR. Low back pain in professional golfers: the role of associated hip and low range-of-motion deficits. American Journal of Sports Medicine 2004;32(2):494e7. Vad VB, Gebeh A, Dines D, Altchek D, Norris B. Hip and shoulder internal rotation range of motion deficits in professional tennis players. Journal of Science and Medicine in Sport 2003;6(1):71e5. Van Dillen LR, Bloom NJ, Gombatto SP, Susco TM. Hip rotation range of motion in people with and without low back pain who participate in rotation-related sports. Physical Therapy in Sport 2008;9(2):72e81. Van Dillen LR, Gombatto SP, Collins DR, Engsberg JR, Sahrmann SA. Symmetry of timing of hip and lumbopelvic rotation motion in 2 different subgroups of people with low back pain. Archives of Physical Medicine and Rehabilitation 2007;88(3):351e60. Van Dillen LR, Maluf KS, Sahrmann SA. Further examination of modifying patientpreferred movement and alignment strategies in patients with low back pain during symptomatic tests. Manual Therapy 2009;14(1):52e60. Yamaji O, Imai N, Arima T. Lumbar disorders of the judô players. Tokay Journal of Sports Medicine and Science 1992;4:46e51.