Comparison of the prevalence of myofascial trigger points of muscles acting on knee between patients with moderate degree of knee osteoarthritis and healthy matched people

INTRODUCTION

Trigger points have been implicated in the development of several musculoskeletal disorders. Trigger points harbored in lower limb muscles might represent a ubiquitous source of pain in patients with knee osteoarthritis (OA). This study was carried out to evaluate the prevalence of Myofascial Trigger Points (MTrPs) in muscles acting on the knee in patients with OA.

METHODS

Thirty-seven patients aged at least 55 years old with a moderate degree of OA (grade III of Kellgren and Lawrence scale) were recruited. Thirty asymptomatic people, matched on age and body mass index, were considered as the control group. Ten muscles acting on the knee joint were selected. Taut bands were also identified using a skin rolling method. A pressure of 3 kg/cm² was used to identify myofascial trigger points in all muscles except the popliteus (8 kg/cm²).

RESULTS

Chi-square was performed to compare the prevalence of trigger points between the groups. The McNemar test was administered to compare the prevalence of trigger points in the right and left sides of participants. Prevalence of the trigger points was significantly higher in patients with knee OA compared with asymptomatic people in all muscles except for right (p = 0.17) and left (p = 0.41) rectus femoris, right (p = 0.61) and left (p = 0.22) sartorius and left biceps femoris (p = 0.08). Comparison of the prevalence of MTrPs bilaterally revealed that only the right and left sartorius differed significantly (p = 0.008).

CONCLUSIONS

The prevalence of MTrPs in the muscles acting on the knee joint is higher in patients with a moderate degree of knee OA compared with asymptomatic subjects.

Prevalence and sensitivity of trigger points in lumbo-pelvic-hip muscles in patients with patellofemoral pain syndrome

OBJECTIVES

Changes in the activity of the lumbo-pelvic-hip muscles have been established as a major cause of patellofemoral pain syndrome (PFPS), a common orthopedic problem. The present study aimed to compare the prevalence and sensitivity of myofascial trigger points (MTrPs) in lumbo-pelvic-hip muscles in persons with and without PFPS.

METHODS

Thirty women with PFPS and 30 healthy women 18-40 years old were recruited for this study. The prevalence of MTrPs was assessed by palpation, and pressure algometry was used to measure the pressure pain threshold. This study evaluated the areas where MTrPs are most commonly found in the lumbar muscles (internal oblique, erector spinae and quadratus lumborum), pelvic muscles (gluteus maximus, gluteus medius, gluteus minimus and piriformis), and hip muscles (hip adductor, quadriceps, hamstring, tensor fascia lata and sartorius). Independent t-tests were used to compare mean pressure pain thresholds between the two groups. Chi-squared tests were used to compare the prevalence of MTrPs.

RESULTS

The prevalence of MTrPs was significantly higher in most of the lumbo-pelvic-hip muscles in patients with PFPS compared to healthy persons. However, there were no significant differences between groups in the prevalence of MTrPs in the gluteus minimus or adductor muscles. The pressure pain threshold in lumbo-pelvic-hip muscles was lower in patients with PFPS compared to healthy participants.

CONCLUSION

In patients with PFPS the prevalence of MTrPs in the lumbo-pelvic-hip region was higher, and the pressure pain threshold was lower, than in healthy people. Thus therapy to treat PFPS should target the lumbo-pelvic-hip muscles.

A randomized controlled trial comparing the long-term use of soft lumbosacral orthoses at two different pressures in patients with chronic nonspecific low back pain

BACKGROUND

There is concern that wearing soft lumbosacral orthoses for prolonged periods may impair motor function. Moreover, the pressure applied by lumbosacral orthoses on the abdominal wall is usually ignored when these orthoses are prescribed.

METHOD

In this randomized controlled trial study, 48 patients with chronic nonspecific low back pain were randomly divided into high pressure, normal pressure and control groups. All groups received medication for 4 weeks. The normal pressure and high pressure groups, in addition to medication, used soft lumbosacral orthoses at normal pressure and 50% increased pressure, respectively. Motor function outcome measures were strength, endurance, proprioception and electromyographic activity of the trunk muscles. Clinical outcome measures were pain and disability, which were evaluated in two sessions before and after a 4-week interval.

FINDINGS

Isometric strength, endurance and most of the electromyographic parameters were generally unaffected by wearing the lumbosacral orthosis. Pain improved in all groups, and disability and proprioception improved in the high pressure and normal pressure groups. Between-group differences in these three measures indicated better results in the lumbosacral orthoses groups than in the control group. The improvements in pain and proprioception were significantly greater in the high pressure group than the normal pressure group.

INTERPRETATION

Long-term use of lumbosacral orthoses had no significant adverse effects on motor function or clinical factors in patients with chronic low back pain. Increasing lumbosacral orthosis tightness may improve motor functioning and the clinical efficacy of the orthosis.

CLINICAL TRIAL REGISTRATION NUMBER

Code: IRCT201708192391N38.

Changes in Knee Vastii Muscle Activity in Women with Patellofemoral Pain Syndrome During the Menstrual Cycle

BACKGROUND

Changes in hormonal levels during the menstrual cycle are known to affect muscle electromyographic (EMG) activity, but no studies have investigated the effect of hormonal changes on the EMG activity of muscles around the knee in patients with patellofemoral pain syndrome (PFPS).

OBJECTIVE

To evaluate the EMG activity of the vastus medialis obliquus (VMO) and vastus lateralis (VL) muscles during toe rise and heel rock tasks in different phases of the menstrual cycle in women with PFPS.

DESIGN

Cross sectional study.

SETTING

Rehabilitation Research Center at the School of Rehabilitation Sciences of Shiraz University of Medical Sciences.

PARTICIPANTS

Ten women with PFPS between 18 and 40 years of age.

INTERVENTION

Not applicable.

MAIN OUTCOME MEASURES

The VL/VMO amplitude ratio and differences between onset (onset VL-onset VMO) of vastii muscle activity were measured in the affected limb during rise and rock tasks in the follicular and ovulatory phases of the menstrual cycle. The signals were analyzed with MATLAB software.

RESULTS

During both tasks, there were no significant changes in onset differences in vastii muscles between the ovulatory and follicular phases. However, the amplitude ratio (VL/VMO) was significantly lower in the ovulatory phase compared to the follicular phase (P = .035 for rise tasks and .010 for rock tasks).

CONCLUSION

The menstrual cycle may affect some EMG parameters. These factors can be taken into account when planning sports and rehabilitation training programs.