Acute changes of hip joint range of motion using selected clinical stretching procedures: A randomized crossover study

BACKGROUND

Hip adductor flexibility and strength is an important component of athletic performance and many activities of daily living. Little research has been done on the acute effects of a single session of stretching on hip abduction range of motion (ROM).

OBJECTIVES

The aim of this study was to compare 3 clinical stretching procedures against passive static stretching and control on ROM and peak isometric maximal voluntary contraction (MVC).

DESIGN

Using a randomized crossover study design, a total of 40 participants (20 male and 20 female) who had reduced hip adductor muscle length attended a familiarization session and 5 testing sessions on non-consecutive days.

METHOD

Following the warm-up and pre-intervention measures of ROM and MVC, participants were randomly assigned 1 of 3 clinical stretching procedures (modified lunge, multidirectional, and joint mobilization) or a static stretch or control condition. Post-intervention measures of ROM and MVC were taken immediately following completion of the assigned condition.

RESULTS

An ANOVA using a repeated measure design with the change score was conducted. All interventions resulted in small but statistically significant (p < 0.05) increases (1.0°-1.7°) in ROM with no inter-condition differences except one. Multidirectional stretching was greater than control (p = 0.031).

CONCLUSIONS

These data suggest that a single session of stretching has only a minimal effect on acute changes of hip abduction ROM. Although hip abduction is a frontal plane motion, to effectively increase the extensibility of the structures that limit abduction, integrating multi-planar stretches may be indicated.

Effects of low back pain and of stabilization or movement-system-impairment treatments on induced postural responses: A planned secondary analysis of a randomised controlled trial

BACKGROUND

Motor retraining for non-specific chronic low back pain (LBP) often focuses on voluntary postural tasks. This training, however, may not transfer to other known postural impairments, such as automatic postural responses to external perturbations.

OBJECTIVES

To evaluate the extent current treatments of motor retraining ameliorate impaired postural coordination when responding to a perturbation of standing balance.

DESIGN

Planned secondary analysis of a prospectively registered (NCT01362049), randomized controlled trial with a blinded assessor.

METHOD

Sixty-eight subjects with chronic, recurrent, non-specific LBP were allocated to perform a postural response task as a secondary assessment one week before and one week after receiving either stabilization or Movement System Impairment (MSI)-directed treatment over 6 weekly 1-h sessions plus home exercises. For assessment, subjects completed the Oswestry disability and numeric pain rating questionnaires and then performed a postural response task of maintaining standing balance in response to 3 trials in each of 4 randomly presented directions of linear surface translations of the platform under the subjects' feet. Integrated amplitudes of surface electromyography (EMG) were recorded bilaterally from the rectus abdominis (RA), internal oblique (IO), and external oblique (EO) muscles during the postural response task.

RESULTS

No significant effects of treatment on EMG responses were evident. Oswestry and numeric pain ratings decreased similarly following both treatments.

CONCLUSIONS

Stabilization and MSI-directed treatments do not affect trunk EMG responses to perturbations of standing balance in people with LBP, suggesting current methods of motor retraining do not sufficiently transfer to tasks of reactive postural control.

Effects of low back pain stabilization or movement system impairment treatments on voluntary postural adjustments: a randomized controlled trial

BACKGROUND

People with low back pain (LBP) exhibit impaired anticipatory postural adjustments (APAs).

OBJECTIVE

To evaluate whether current motor retraining treatments address LBP-associated changes in movement coordination during tasks that do and do not require APAs.

DESIGN

Prospectively registered randomized controlled trial with a blinded assessor.

SETTING

Outcome evaluations occurred in a university laboratory; treatments were carried out in outpatient physical therapy clinics.

PATIENTS

Fifteen subjects without LBP and 33 subjects with chronic, recurrent, and nonspecific LBP.

INTERVENTION

Twelve subjects with LBP received stabilization treatment, 21 received movement system impairment-based treatment, for more than 6 weekly 1-hour sessions plus home exercises.

MEASUREMENTS

Pre- and post-treatment, surface electromyography (EMG) was recorded bilaterally from trunk and leg muscles during unsupported and supported leg-lifting tasks, which did and did not require an APA, respectively. Vertical reaction forces under the contralateral leg were recorded to characterize the APA. Oswestry disability scores and numeric pain ratings were also recorded.

RESULTS

Persons with LBP demonstrated an impaired APA compared with persons without LBP, characterized by increased premovement contralateral force application and increased postmovement trunk EMG amplitude, regardless of the task. After treatments, both groups similarly improved in disability and function; however, APA characteristics did not change (ie, force application or EMG amplitude) in either task.

LIMITATIONS

Treating clinicians were not blinded to treatment allocation, only short-term outcomes were assessed, and main effects of treatment do not rule out nonspecific effects of time or repeated exposure.

CONCLUSIONS

Movement impairments in persons with LBP are not limited to tasks requiring an APA. Stabilization and movement system impairment-based treatments for LBP do not ameliorate and may exacerbate APA impairments (ie, excessive force application and increased post-movement trunk muscle activation).

Outcomes are not different for patient-matched versus nonmatched treatment in subjects with chronic recurrent low back pain: a randomized clinical trial

BACKGROUND CONTEXT

Classification schemas for low back pain (LBP), such as the Treatment-Based Classification and the Movement System Impairment, use common clinical features to subgroup patients with LBP and are purported to improve treatment outcomes.

PURPOSE

To assess if providing matched treatments based on patient-specific clinical features led to superior treatment outcomes compared with an unmatched treatment for subjects with chronic recurrent LBP.

STUDY DESIGN

This study is a randomized controlled trial.

PATIENT SAMPLE

Subjects (n=124) with LBP (≥12 months) with or without recurrences underwent a standardized clinical examination to group them into one of two strata: ineligible or eligible for stabilization exercises based on the Treatment-Based Classification schema. Subjects underwent additional clinical tests to assign them to one of the five possible Movement System Impairment categories.

OUTCOME MEASURES

Questionnaires were collected electronically at Week 0 (before treatment), Week 7 (after the 6-week 1-hour treatment sessions), and 12 months. Using the Oswestry disability index (0-100) and the Numeric Pain Rating Scale (0-10), the primary analysis was performed using the intention-to-treat principle. Secondary outcomes included fear-avoidance beliefs and psychosocial work-related and general health status.

METHODS

After subjects were categorized based on their particular clinical features using both the Treatment-Based Classification and Movement System Impairment schemas, they were randomized into one of two treatments using a 3:1 ratio for matched or unmatched treatments. The treatments were trunk stabilization exercise or Movement System Impairment-directed exercises.

RESULTS

Of the patients allocated to treatment for this study, 76 received a matched treatment and 25 received an unmatched treatment. After treatment, both groups showed a statistically significant improvement in the primary outcome measures and almost all the secondary measures; however, the matched treatment group did not demonstrate superior outcomes at Week 7 or 12 months, except on one of the secondary measures (Graded Chronic Pain Scale [Disability Scale]) (p=.01).

CONCLUSIONS

Providing a matched treatment based on either the Treatment-Based Classification or the Movement System Impairment classification schema did not improve treatment outcomes compared with an unmatched treatment for patients with chronic LBP, except on one secondary disability measure.

Altered postural responses persist following physical therapy of general versus specific trunk exercises in people with low back pain

Interventions that target trunk muscle impairments in people with LBP have been promoted; however, the treatment effects on muscle activation impairments during postural tasks remain unclear. Thus, our objective was to evaluate the effects trunk stabilization vs. general strength and conditioning exercises on the automatic postural response in persons with chronic low back pain (LBP). Fifty-eight subjects with chronic, recurrent LBP (n = 58) (i.e., longer than six months) were recruited and randomly assigned to one of two, 10-week physical therapy programs: stabilization (n = 29) or strength and conditioning (n = 29). Pain and function were measured at 11 weeks and 6 months post-treatment initiation. To quantify postural following support surface perturbations, surface electrodes recorded electromyography (EMG) of trunk and leg muscles and force plates recorded forces under the feet, to calculate the center of pressure. Both groups demonstrated significant improvements in pain and function out to 6 months. There were also changes in muscle activation patterns immediately post-treatment, but not at 6 months. However, changes in center of pressure (COP) responses were treatment specific. Following treatment, the stabilization group demonstrated later onset of COP displacement, while the onset of COP displacement in the strengthening group was significantly earlier following treatment. Despite two different treatments, clinical improvements and muscle activation patterns were similar for both groups, indicating that the stabilization treatment protocol does not preferentially improve treatment outcomes or inter-muscle postural coordination patterns for persons with LBP.

CLINICAL TRIAL REGISTRATION NUMBER

NCT01611792.

Protocol to assess the neurophysiology associated with multi-segmental postural coordination

Anticipatory postural adjustments (APAs) stabilize potential disturbances to posture caused by movement. Impaired APAs are common with disease and injury. Brain functions associated with generating APAs remain uncertain due to a lack of paired tasks that require similar limb motion from similar postural orientations, but differ in eliciting an APA while also being compatible with brain imaging techniques (e.g., functional magnetic resonance imaging; fMRI). This study developed fMRI-compatible tasks differentiated by the presence or absence of APAs during leg movement. Eighteen healthy subjects performed two leg movement tasks, supported leg raise (SLR) and unsupported leg raise (ULR), to elicit isolated limb motion (no APA) versus multi-segmental coordination patterns (including APA), respectively. Ground reaction forces under the feet and electromyographic activation amplitudes were assessed to determine the coordination strategy elicited for each task. Results demonstrated that the ULR task elicited a multi-segmental coordination that was either minimized or absent in the SLR task, indicating that it would serve as an adequate control task for fMRI protocols. A pilot study with a single subject performing each task in an MRI scanner demonstrated minimal head movement in both tasks and brain activation patterns consistent with an isolated limb movement for the SLR task versus multi-segmental postural coordination for the ULR task.

Shoulder functional assessments in persons with chronic neck/shoulder pain and healthy subjects: Reliability and effects of movement repetition

OBJECTIVE

Obtaining reliable functional capacity measures from injured workers is an essential part of the return to work (RTW) process. The present study compares shoulder functional outcomes between healthy individuals and others with neck/shoulder pain, assesses reliability and examines the influence of repetitive movements on shoulder function.

METHODS

Subjects performed trials of flexion and abduction active range of motion (ROM), and cumulative power output (PO) in a pushing/pulling task on the Baltimore Therapeutic Equipment Simulator II in two consecutive sessions. Tasks were assessed before and after performing a repetitive arm task, during which heart rate (HR) was recorded, until scoring 8 on the Borg CR-10 scale or on a 11-point numeric rating scale (NRS) for pain.

PARTICIPANTS

Persons with chronic neck/shoulder pain (intensity ≥ 3/10 for > 3 months) (n = 16) and an age- and sex-matched control group (n = 16).

RESULTS

Functional shoulder measures demonstrated strong inter-session reliability, except PO in the pain group. Average repetitive task duration was shorter in the pain group (4 min vs. 7 min).

CONCLUSIONS

The protocol detected both pain- and time-related impairments, with HR and PO being sensitive to movement duration and ROM to pain.

Differences in posture-movement changes induced by repetitive arm motion in healthy and shoulder-injured individuals

BACKGROUND

Neck/Shoulder pain is linked to movement repetition, awkward postures, prolonged maintenance of static postures, and muscular fatigue. Studies have examined the influence of pain and fatigue on movement characteristics, but few reported multi-dimensional adaptations to movement repetition. We compared the adaptations measured in three-dimensions during a repetitive reaching task in persons with chronic neck/shoulder pain and healthy subjects.

METHODS

A shoulder-injured group (intensity >3/10, duration >3 consecutive months) and an age-sex-matched control group (n=16 in each) performed a repetitive reaching task to voluntary termination. Kinematics, kinetics, heart rate and muscle activity were recorded throughout. Power output on a 10-s pushing/pulling task was assessed pre- and post-reaching. Group comparisons were made in absolute time and at task end.

FINDINGS

Control subjects performed the task 55% longer than the pain group; yet, both groups demonstrated task-related increased heart rate (6 beats per minute) and decreased power output (6 W). Throughout the task, the pain group demonstrated: higher supraspinatus activity, and less elbow flexion and endpoint movement. The control group increased movement amplitude of the endpoint, elbow, and shoulder, while the pain group moved the shoulder less and increased center of mass excursion to maintain the task.

INTERPRETATION

Both groups adapted to the task in unique ways. The control group continually increased elbow and endpoint range of motion, bringing the arm closer to the targets, possibly to prolong task performance. The pain group used a fixed, en block arm strategy, likely to reduce the load on the injured structures; however, this may place other structures at risk for pain and injury.