Hip abductor muscle weakness and slowed turning motion in people with knee osteoarthritis

Hip Abductor Weakness and Its Association With New or Worsened Knee Pain: Data From the Multicenter Osteoarthritis Study

OBJECTIVE

Hip abductors, important for controlling pelvic and femoral orientation during gait, may affect knee pain. Our objective was to evaluate the relation of hip abductor strength to worsened or new-onset frequent knee pain. Given previously noted associations of knee extensor strength with osteoarthritis in women, we performed sex-specific analyses.

METHODS

We used data from the Multicenter Osteoarthritis study. Hip abductor and knee extensor strength was measured. Knee pain was assessed using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) questionnaire and a question about frequent knee pain at baseline (144-month visit), and 8, 16, and 24 months thereafter. Knee pain outcomes were worsened knee pain (2-point increase in WOMAC pain) and incident frequent knee pain (answering yes to the frequent knee pain question among those without frequent knee pain at baseline). Leg-specific analyses tested hip abductor strength as a risk factor for worsened and new frequent knee pain, adjusting for potential covariates. Additionally, we stratified by knee extensor strength (high versus low).

RESULTS

Among women, compared to the highest quartile of hip abductor strength, the lowest quartile had 1.7 (95% confidence interval [95% CI] 1.1-2.6) times the odds of worsened knee pain; significant associations were limited to women with high knee extensor strength (odds ratio 2.0 [95% CI 1.1-3.5]). We found no relation of abductor strength to worsening knee pain in men or with incident frequent knee pain in men or women.

CONCLUSION

Hip abductor weakness was associated with worsening knee pain in women with strong knee extensors, but not with incident frequent knee pain in men or women. Knee extensor strength may be necessary, but not sufficient, to prevent pain worsening.

Compensatory gait mechanics in person with multiple toe amputation: A single case report

This case highlights the biomechanical influence of toe amputation on contralateral limb force elevation, possibly through reduced ipsilateral plantar flexor torque production. These findings provide insight into toe amputation-related compensatory gait mechanics with greater inter-limb asymmetry, which may increase the risk of musculoskeletal comorbidities, including osteoarthritis in contralateral limb.

Determination of reference intervals for knee motor functions specific to patients undergoing knee arthroplasty

Background

In patients with knee osteoarthritis (KOA) undergoing knee arthroplasty (KA), lower-limb motor function tests are commonly measured during peri-surgical rehabilitation. To clarify their sources of variation and determine reference intervals (RIs), a multicenter study was performed in Japan.

Methods

We enrolled 545 KOA patients (127 men; 418 women; mean age 74.2 years) who underwent KA and followed a normal recovery course. The surgical modes included total KA (TKA), minimally invasive TKA (MIS-TKA), and unicompartmental KA (UKA). Motor functions measured twice before and two weeks after surgery included timed up-and-go (TUG), maximum walking speed (MWS), extensor and flexor muscle strength (MS), and knee range of motion (ROM). Multiple regression analysis was performed to evaluate their sources of variation including sex, age, BMI, and surgical mode. Magnitude of between-subgroup differences was expressed as SD ratio (SDR) based on 3-level nested ANOVA. SDR≥0.4 was set as the threshold for requiring RIs specific for each subgroup.

Results

Before surgery, age-related changes exceeding the threshold were observed for TUG and MWS. Between-sex difference was noted for extensor and flexor MS, but extension and flexion ROMs were not influenced by sex or age. After surgery, in addition to similar influences of sex and age on test results, surgical modes of UKA and MIS-TKA generally had a favorable influence on MWS, extensor MS, and flexion ROM. All motor function test results showed a variable degree of skewness in distribution, and thus RIs were basically derived by the parametric method after Gaussian transformation of test results.

Conclusions

This is the first study to determine RIs for knee motor functions specific to KOA patients after careful consideration of their sources of variation and distribution shapes. These RIs facilitate objective implementation of peri-surgical rehabilitation and allow detection of patients who deviate from the normal course of recovery.

Low Level Laser Therapy in Knee Osteoarthritis: A Narrative Review

Knee osteoarthritis (KOA) is the most common musculoskeletal disorder, especially in middle up to old age. KOA also results in many complications like changes in gait. Nowadays, changes in lifestyle and the reduced physical activity make people more vulnerable to KOA. Therefore, considering the increasing prevalence of KOA in many societies and the costs imposed on the afflicted people and their governments, providing conservative management approaches with a view to saving time and money is important. There are an assortment of conservative strategies in the management of KOA including low level laser therapy (LLLT). Since the introduction of lasers in the medical field in 1960, various types of lasers with widespread administration programs are used for medical conditions from cosmetics to surgery. However, there are conflicting findings on the application of lasers in osteoarthritis. To discuss the basis of the highest level of evidence, only systematic reviews with or without meta-analyses published up to January 2019 were included in the present work. In this regard, Scopus, PEDro, Medline, ISI Web of Science, Cochrane, PubMed, Irandoc, Iran Medex, Magiran, and SID were searched to retrieve articles in English or Persian. A total of 22 systematic reviews and meta-analyses were found, 14 of which were included in this study. The accepted articles were published between 1991 and up to 2019. The purpose of this narrative review was to investigate the effect of LLLT on pain and function in subjects with KOA. The result of the present review may help clinicians in making evidence-based decisions on optimal care in relation to administering LLLT.