Relationship Between Proprioception and Endurance Functionality of the Cervical Flexor Muscles in Chronic Neck Pain and Asymptomatic Participants.

OBJECTIVE: The purpose of this study was to compare the relationship between flexion endurance capacity and joint position error in participants with or without chronic neck pain (CNP). METHODS: Sixty-one CNP and 60 asymptomatic volunteers participated in this cross-sectional, case-control, and correlational analysis study. The measured variables included absolute and constant joint repositioning errors in the sagittal and horizontal directions, clinical flexor endurance test score, pain intensity, and neck disability index. RESULTS: The groups did not statistically differ in flexion endurance (P > .05). The CNP group had a smaller absolute error on the right (P < .01) and left (P = .01) rotation and an overshooting error pattern in the flexion direction (P < .05). But the asymptomatic group did not exhibit any over-/undershooting pattern tendency (P > .05). Although flexion endurance was not correlated with any of the joint repositioning error components in either group, pain and disability scores were significantly correlated with left rotation absolute error (r = -0.34 and ρ = -0.37, respectively). CONCLUSION: The clinical cervical flexor endurance test, ignoring the relative contribution of the deep and superficial groups of muscles, may not efficiently characterize CNP patients.

Effect of the Abdominal Hollowing and Bracing Maneuvers on Activity Pattern of the Lumbopelvic Muscles During Prone Hip Extension in Subjects With or Without Chronic Low Back Pain: A Preliminary Study.

OBJECTIVE: The purpose of this study was to compare the effect of abdominal hollowing (AH) and abdominal bracing (AB) maneuvers on the activity pattern of lumbopelvic muscles during prone hip extension (PHE) in participants with or without nonspecific chronic low back pain (CLBP). METHODS: Twenty women with or without CLBP participated in this cross-sectional observational study. The electromyographic activity (amplitude and onset time) of the contralateral erector spinae (CES), ipsilateral erector spinae (IES), gluteus maximus, and biceps femoris muscles was measured during PHE with and without abdominal maneuvers. A 3-way mixed model analysis of variance and post hoc tests were used for statistical analysis. RESULTS: Between-group comparisons showed that the CES onset delay during PHE alone was greater (P = .03) and the activity level of IES, CES, and biceps femoris in all maneuvers (P < .05) was higher in patients with CLBP than in asymptomatic participants. In asymptomatic participants, PHE + AH significantly decreased the signal amplitude (AMP) of IES (P = .01) and CES (P = .02) muscles. In participants with CLBP, IES muscle AMP was lower during PHE + AH compared with PHE + AB and PHE alone. With regard to onset delay, the results also showed no significant difference between maneuvers within either of the 2 groups (P > .05). CONCLUSIONS: Performance of the AH maneuver decreased the erector spinae muscle AMP in both groups, and neither maneuver altered the onset delay of any of the muscles in either group. The low back pain group showed higher levels of activity in all muscles (not statistically significant in gluteus maximus during all maneuvers). The groups were similar according to the onset delay of any of the muscles during either maneuver.

Balance recovery reactions in individuals with recurrent nonspecific low back pain: Effect of attention.

People who suffer from Low Back Pain (LBP) demonstrate impaired postural control. Deficits in sensory-motor systems have been proposed to be related to these changes. Considering higher cognitive process contribution to postural control, the aim of this study was to investigate the effects of cognitive load on balance control of patients with LBP. Twenty subjects with recurrent non-specific LBP and 20 healthy controls participated. They stood on a moveable platform with each foot placed on a separate force plate. They were asked to maintain their balance (a) while expecting translations of the support surface at two sizes of perturbation (b) with and without performing a cognitive (auditory Stroop) task. The outcomes included reaction time (RT), latency, initial velocity and amplitude of center of pressure response for balance, and RT for cognitive performance. Compared to the healthy group, LBP group demonstrated delayed RT and latency, and reduced initial velocity (P<0.05). Moreover, they had slower Stroop RT (F=70.88, P<0.001). Concurrent performance of tasks resulted in increased Stroop RT (F=3.42, P=0.03) and adaptation in initial velocity (F=6.70, P=0.01). At the smaller size of perturbation, cognitive load increased velocity in LBP group but decreased this variable in the healthy group. When the cognitive load was added at the larger size of perturbation, velocity of response decreased in LBP group (P<0.05). These findings imply altered cognitive regulation of dynamic balance in patients with LBP and suggest that the adopted strategy might alter depending upon the characteristics of the postural challenge.

Change in lumbar lordosis during prone lying knee flexion test in subjects with and without low back pain.

BACKGROUND: Prone lying knee flexion (PLKF) is one of the clinical tests used for assessment of the lumbo-pelvic movement pattern. Considerable increase in lumbar lordosis during this test has been considered as impairment of movement patterns in lumbar-pelvic region. However, no study has directly evaluated the change in lordosis during active PLKF test in subjects with low back pain (LBP). The purpose of this study was to investigate the change of lumbar lordosis in PLKF test in subjects with and without LBP. METHODS: A convenience sample of 80 subjects participated in the study. Subjects were categorized into two groups: those with chronic non-specific LBP (N = 40, mean age: 40.84 ± 17.59) and with no history of LBP (N = 40, mean age: 23.57 ± 10.61). Lumbar lordosis was measured with flexible ruler, first in prone position and then on active PKF test in both subjects with and without LBP. Data was analyzed by using statistical methods such as, independent t-test and paired t-test. RESULTS: There were statistically significant differences in lumbar lordosis between prone position and after active PLKF in both subjects with and without LBP (P < 0.0001). The amount of change in lordosis during PLKF test was not significant between the two groups (P = 0.65). However these changes were greater among patients with LBP. CONCLUSION: Increase in lumbar lordosis during this test may be due to excessive flexibility of movement of the lumbar spine in the direction of extension and abnormal movement patterns in the individuals with LBP.

Effect of functional lumbar stabilization exercises on pain, disability, and kinesiophobia in women with menstrual low back pain: a preliminary trial.

OBJECTIVE: The purpose of this preliminary study was to investigate the effect of functional lumbar stabilization exercises on pain, disability, and kinesiophobia in women with menstrual low back pain (LBP). METHODS: Thirty women with menstrual LBP participated in the study. Subjects were assigned to a control group (n = 10, mean age = 25.1 ± 4.7 years) and an intervention group (n = 20, mean age = 21.7±2.4 years). Treatment for the intervention group consisted of functional lumbar stabilization exercises, 10 repetitions each, 3 times a day, for 3 consecutive months. The women in the control group received no exercise and performed their regular activity daily living. Pain intensity using a Numeric Pain Scale (NPS), Oswestry Disability Index (ODI), Roland-Morris Questionnaire (RMQ), and Tampa Scale of Kinesiophobia (TSK) was collected at baseline and at the end of 3 months in both groups. RESULTS: Statistical analysis (paired t test) revealed a significant decrease in NPS, ODI, RMQ, and TSK after treatment in the intervention group. No significant difference in NPS, ODI, RMQ, or TSK was found between pre- and postmeasurement scores in the control group. In the analysis of covariance, controlling for pretest scores, a significant difference was found between the 2 groups in the postmeasurement score of NPS (P = .01), ODI (P < .001), RMQ (P = .002), and TSK (P = .04). CONCLUSION: Lumbar stabilization exercises were shown to improve pain, disability, and kinesiophobia during menstrual LBP for subjects who participated in this preliminary study compared to those who did not receive the intervention.

Altered muscular activation during prone hip extension in women with and without low back pain.

BACKGROUND: Altered movement pattern has been associated with the development of low back pain (LBP). The purpose of this study was to investigate the activity pattern of the ipsilateral erector spinae (IES) and contralateral erectorspinae (CES), gluteus maximus (GM) and hamstring (HAM) muscles during prone hip extension (PHE) test in women with and without LBP. A cross-sectional non-experimental design was used. METHODS: Convenience sample of 20 female participated in the study. Subjects were categorized into two groups: with LBP (n = 10) and without LBP (n = 10). The electromyography (EMG) signal amplitude of the tested muscles during PHE (normalized to maximum voluntary electrical activity (MVE)) was measured in the dominant lower extremity in all subjects. RESULTS: Statistical analysis revealed greater normalized EMG signal amplitude in women with LBP compared to non-LBP women. There was significant difference in EMG activity of the IES (P = 0.03) and CES (P = 0.03) between two groups. However, no significant difference was found in EMG signals of the GM (P = 0.11) and HAM (P = 0.14) among two groups. CONCLUSION: The findings of this study demonstrated altered activation pattern of the lumbo-pelvic muscles during PHE in the women with chronic LBP. This information is important for investigators using PHE as either an evaluation tool or a rehabilitation exercise.

The relationship between hip abductor muscle strength and iliotibial band tightness in individuals with low back pain.

BACKGROUND: Shortening of the iliotibial band (ITB) has been considered to be associated with low back pain (LBP). It is theorized that ITB tightness in individuals with LBP is a compensatory mechanism following hip abductor muscle weakness. However, no study has clinically examined this theory. The purpose of this study was to investigate the muscle imbalance of hip abductor muscle weakness and ITB tightness in subjects with LBP. METHODS: A total of 300 subjects with and without LBP between the ages of 20 and 60 participated in this cross-sectional study. Subjects were categorized in three groups: LBP with ITB tightness (n = 100), LBP without ITB tightness (n = 100) and no LBP (n = 100). Hip abductor muscle strength was measured in all subjects. RESULTS: Analysis of Covariance (ANCOVA) with the body mass index (BMI) as the covariate revealed significant difference in hip abductor strength between three groups (P < 0.001). Post hoc analysis showed no significant difference in hip abductor muscle strength between the LBP subjects with and without ITB tightness (P = 0.59). However, subjects with no LBP had significantly stronger hip abductor muscle strength compared to subjects with LBP with ITB tightness (P < 0.001) and those with LBP without ITB tightness (P < 0.001). CONCLUSION: The relationship between ITB tightness and hip abductor weakness in patients with LBP is not supported as assumed in theory. More clinical studies are needed to assess the theory of muscle imbalance of hip abductor weakness and ITB tightness in LBP.