Increased Quadriceps Strength Research Articles

'Real world' clinical implementation of blood flow restriction therapy does not increase quadriceps strength after quadriceps tendon autograft ACL reconstruction.

To retrospectively compare strength outcomes of individuals undergoing postoperative rehabilitation following quadriceps tendon (QT) autograft anterior cruciate ligament reconstruction (ACLR) with and without blood flow restriction therapy. A retrospective review of consecutive patients undergoing ACLR with QT autograft with a minimum of two quantitative postoperative isometric strength assessments via an electromechanical dynamometer (Biodex) was included. Demographics, surgical variables and strength measurement outcomes were compared between patients undergoing blood flow restriction therapy as part of postoperative rehabilitation versus those who did not. Eighty-one (81) patients met the inclusion criteria. No differences were found in demographic and surgical characteristics between those who received blood flow restriction compared with those who did not. While both groups had improvements in quadriceps peak torque and limb symmetry index (LSI; defined as peak torque of the operative limb divided by the peak torque of the nonoperative limb) over the study period, the blood flow restriction group had significantly lower mean peak torque of the operative limb at first Biodex strength measurement (95.6 vs. 111.2 Nm; p = 0.03). Additionally, the blood flow restriction group had a significantly lower mean LSI than those with no blood flow restriction at the second Biodex measurement timepoint (81% vs. 90%; p = 0.02). No other significant differences were found between the strength outcomes measured. Results of this study show that the 'real world' clinical implementation of blood flow restriction therapy to the postoperative rehabilitation protocol following QT autograft ACLR did not result in an increase in absolute or longitudinal changes in quadriceps strength measurements. A better understanding and standardisation of the use of blood flow restriction therapy in the rehabilitation setting is necessary to delineate the true effects of this modality on strength recovery after QT autograft ACLR. Level III.

Is Quadriceps-Strengthening Exercises (QSE) in Medial-Compartment Knee Osteoarthritis with Neutral and Varus Malalignment a Paradox? - A Risk-Appraisal of Strength-Training on Disease Progression.

The present inquiry seeks to investigate whether the current regimens of QSEs (Quadriceps-Strengthening Exercises) aggravate the disease while mitigating symptoms. A comparative study was conducted on 32 patients with medial compartment osteoarthritis of knees. While the neutral group of 16 patients was constituted of those with an anatomical-lateral-femoro-tibial-angle (aFTA) 176-180º, varus group comprised an equal number of patients with an aFTA >180º. A home-based 12-week strength-training program involving weekly visits to hospital for supervised sessions was administered. The outcome measures were visual-analog-scale (VAS), medial patello-femoral joint tenderness (MPFJT), time-up-and-go-test (TUGT), stair-climb test, step test, WOMAC, IKDC scores, aFTA, hip-knee-ankle (HKA) angle, lateral-tibio-femoral-joint-separation (LTFJS), and horizontal-distance-from-centre-of-knee-to-Mikulicz-line. There was a significant increase in quadriceps strength (p<0.01) in both groups. Values for neutral group with VAS score (p=0.01), MPFJT (p=0.01), TUGT (p=0.01), timing of the stair climb test (p=0.01), WOMAC (p<0.01), and IKDC (p=0.03) were better compared to varus group with VAS score (p=0.13), MPFJT (p=0.03), TUGT (p=0.90), timing of stair climb test (p=0.68), WOMAC (p<0.02), and IKDC (p=0.05). Varus group also showed an increase in aFTA and LTFJS in 12 patients, increase in HKA in 11, and increase in horizontal distance from the centre of knee to the Mikulicz line in 7 patients. The present study brings to the fore the paradoxical role played by QSEs in management of medial knee OA. While there is a radiological progression of the disease in both neutral and varus mal-aligned knees more so in the latter than the former.

Joint pressure stimuli increase quadriceps strength and neuromuscular activity in patients with knee osteoarthritis

The study investigated the effects of periarticular knee pressure stimuli on quadriceps strength and neuromuscular activity in subjects with knee osteoarthritis. Twenty-five subjects with knee osteoarthritis and 25 age-matched healthy controls performed maximal voluntary knee extension tasks on an isometric dynamometer. Three different pressure stimuli (no-pressure, 60-mmHg, 120-mmHg) were applied using a sphygmomanometer via the cuff covering the knee joint. Peak torque and root-mean-square peak of rectus femoris (RF), vastus medialis (VM), and vastus lateralis (VL) were collected and normalized for the no-pressure condition (nTorque-peak and nRMS-peak). Normalized Torque-peak increased from no-pressure to 60-mmHg and 120-mmHg in patients, which revealed higher nTorque-peak during 60-mmHg (MD: 10.9%, IC95: 1.8%, 20.1%, p = 0.020) and 120-mmHg (MD: 16.0%, IC95: 4.4%, 27.6%, p = 0.008) conditions than healthy subjects. Moreover, nRMS-peak increased from no-pressure to 60-mmHg for RF, from no-pressure to 120-mmHg for RF, VM and VL, and from 60-mmHg to 120 mm-Hg for VL in patients. Patients revealed higher nRMS-peak of RF and VM during 60-mmHg and 120-mmHg conditions than healthy subjects. Periarticular knee pressure stimuli enhanced quadriceps strength and neuromuscular activity in subjects with knee osteoarthritis. This approach may represent a new strength training modality in patients with neuromuscular activation deficits for knee osteoarthritis.

Effect of Tai Chi on knee pain and muscle strength in middle-aged and older adults with knee osteoarthritis: a randomized controlled trial protocol

BackgroundKnee osteoarthritis (KOA) is a common public health problem and a leading cause of long-term pain, decreased muscle strength, and even disability. Tai Chi has been proved effective and highly recommended for KOA management worldwide. However, little is known about its benefits on quadriceps strength which is closely associated with relieving knee pain. This trial is designed to evaluate the efficacy and safety of Tai Chi on knee pain and muscle strength in middle-aged and older adults with KOA.MethodsA total of 100 participants will be randomly divided into a Tai Chi group (TC group) (1x/week for 12 weeks) and a control group with a health education and stretching program (1x/week for 12 weeks) with a follow-up period of 6 weeks. The primary outcome is the change of Western Ontario and McMaster Universities (WOMAC) pain subscale at week 12 compared with baseline. Secondary outcomes include WOMAC stiffness and function subscales, data from isokinetic dynamometry, gait analysis with electromyography (EMG), and a 36-item short form health survey (SF-36). The daily dose of pain-relieving medication will also be recorded. All adverse effects will be assessed by the Treatment Emergent Symptom Scale (TESS).DiscussionWe expect this randomized trial to evaluate the effectiveness of Tai Chi on relieving pain and increasing quadriceps strength in KOA patients. This protocol, if proven effective, will contribute to providing a promising alternative intervention for middle-aged and older adults with KOA.Trials registration numberThis trial has been registered in the China Clinical Trials Registry (registration number: ChiCTR2300069339).

Preoperative predictors for return to physical activity following anterior cruciate ligament reconstruction (ACLR): a systematic review

BackgroundRates of return to physical activity after anterior cruciate ligament reconstruction surgery are sub-optimal. Optimising presurgical treatment may improve return rates. The purpose of this systematic review was to identify modifiable preoperative predictors for return to physical activity after anterior cruciate ligament reconstruction.MethodsSeven electronic databases (CINAHL, MEDLINE and SPORTDiscus via EBSCOhost, AMED, PsycINFO and EMBASE via OVID and Web of Science) were searched from inception to 31 March 2023. The population of focus was adults aged 18–65 who had undergone primary anterior cruciate ligament reconstruction. Studies needed to identify at least one potential modifiable preoperative predictor variable and the relationship between the predictor(s) and return to physical activity. All time-points of assessment and study designs were included. Data extraction was completed by one reviewer and verified by a second reviewer. Two reviewers completed the risk of bias assessment using the Quality in Prognostic Studies tool and Grading of Recommendations Assessment, Development and Evaluation system.ResultsThe search identified 2281 studies, eight met the inclusion criteria. Five studies scored ‘high’, and three studies scored ‘moderate’ risk-of-bias. All preoperative predictors were of very low-quality evidence. Five different outcome measures were used to assess return to physical activity including Tegner, Marx, Physical Activity Scale, return to play at the elite level and return to preinjury level (undefined). This was measured between 1- and 10-years post-surgery. Nine preoperative physical, six psychosocial and five demographic/clinical factors were assessed and four were found to be predictive. These included quadriceps strength, psychological profile, patient estimated ability to return and graft type (patella tendon, BPTB).ConclusionVery-low level evidence suggests that increasing quadriceps strength, managing patient expectations of their treatment outcomes, improving motivation to resume preinjury activity levels and considering the use of a BPTB graft will support return to physical activity after ACLR.Trial registrationThis study was prospectively registered in PROSPERO: CRD 42020222567.

Recovery of Quadriceps Strength and Knee Function Using Adjuvant EMG-BF After Primary ACL Reconstruction

Introduction: Immobility and limited usage of operated limbs lead to weakness and atrophy of the muscle after anterior cruciate ligament (ACL) reconstruction. However, training programs for preventing biomechanical risk factors such as lower limb alignment and increased muscular contraction are very limited. Thus, the current study was carried out to evaluate the recovery of quadriceps muscle strength and the improvement of knee function using adjuvant electromyographic biofeedback (EMG-BF) after ACL reconstruction. Methods: This prospective randomized controlled trial was conducted among 40 patients (20=EMG-BF group, 20=Control group) with ACL reconstruction, who were referred to Akhtar Hospital from 2021 to 2022. In the EMG-BF group, EMG BFB was added to the standard rehabilitation protocol, and in the control group, the standard rehabilitation protocol with full postoperative weight-bearing, knee brace (zero degree of extension, 90 degrees of flexion), and electrical stimulation with maximal voluntary isometric knee extension was performed. Each group was intervened for 4 weeks and three sessions of 30 minutes per week. It should be noted that each patient participated in 16 outpatient physiotherapy sessions after surgery. Nicholas Hand-Held Dynamometer (HHD) was used for measuring quadriceps strength, and Knee Outcome Survey-Activities of Daily Living (KOS-ADLs) and Knee Outcome Survey Sports Activities Scale (KOS-SAS) questionnaires were used for assessing the knee function. Results: Four weeks after the treatment, the EMG-BF group showed a significant increase in quadriceps strength (P=0.0001). Quadriceps strength had a significant difference before and after 4 weeks of intervention (P=0.0001), but in the control group, no significant difference was observed (P=0.368). The EMG-BF group had a significant increase in KOS-ADLs and KOS-SAS scores after 4 weeks of intervention (P=0.0001). Conclusion: In our study, isometric strengthening of quadriceps with adjuvant EMG-BF significantly increased the strength of quadriceps and knee function during 4 weeks. EMG-BF is a low risk, low cost, and less invasive intervention and has high safety and adjustment ability. It is a valuable adjuvant method for achieving better functional recovery in a shorter time.

Effect of pulsed electromagnetic field as an intervention for patients with quadriceps weakness after anterior cruciate ligament reconstruction: a double-blinded, randomized-controlled trial

BackgroundThe ultimate goal of anterior cruciate ligament reconstructions (ACLR) is to fulfil the return-to-play (RTP) criteria. Quadriceps muscle strength is one of the key determinants for a patient’s successful return-to-play after ACLR. Quadriceps muscle atrophy can persist beyond the completion of the rehabilitation program in almost half the patients and the reason behind this is still unknown. There are emerging evidences showing that pulsed electromagnetic field (PEMF) can modulate mitochondrial activities for muscle gain. PEMF exposure on top of regular exercise training may promote muscle regeneration and tissue healing.MethodsThis is a double-blinded, randomized controlled trial to investigate the effects of PEMF treatment during the postoperative period on quadriceps muscle strength in ACL injured patient. Adult patients (aged 18–30) with a unilateral ACL injury, total quadriceps muscle volume is equal or more than 7% deficit on involved leg compared with uninvolved leg, sporting injury with a Tegner score of 7+, and both knees without a history of injury/prior surgery will be recruited. To estimate the improvement of patients, isokinetic muscle assessment, ultrasound imaging and MRI for quadriceps muscle thickness, self-reported outcomes with questionnaires, KT-1000 for knee laxity and biomechanical analysis, and Xtreme CT for bone mineral density will be performed. To investigate the mechanism of PEMF therapy on increasing quadriceps strength, samples of blood serum will be drawn before and after intervention.DiscussionThis is the first trial evaluating the effects of PEMF on quadriceps muscle recovery after ACLR. The proposed study addresses a huge research gap by evaluating practical use of PEMF as part of rehabilitation. The proposed study will provide much needed scientific support in the use of this noninvasive treatment modality to facilitate recovery of quadriceps strength after PEMF.Trial registrationClinicalTrials.gov NCT05184023. Registered on 5 January 2022

Pain management and strength gains compared between pneumatic partial weight support treadmill and underwater treadmill in overweight patients with knee osteoarthritis: A randomized controlled trial

Objective To investigate the efficacy of the pneumatic partial weight support treadmill compared to the underwater treadmill (UTM) for reducing pain and increasing quadriceps strength in overweight patients with knee osteoarthritis. Design Non-inferiority trial with a pre-specified 1-point range Methods Participants (N = 109) were randomly assigned to the study (pneumatic partial weight support treadmill) (n = 55) or control (UTM) (n = 54) groups. Patients in both groups started with 50% weight support during the first week, 40% during the second week, and 30% during the third week and until the end of the study. Both groups received exercise for 30 min, 3 times per week for 8 weeks (24 sessions). Outcome measurements, including numerical pain rating scale, Western Ontario and McMaster Universities Osteoarthritis Index pain subscale, quadriceps strength, body weight, 6-min walking test, and quality of life, were evaluated at baseline, 8 weeks, and 12 weeks. Results Only 74 participants completed the study. Numerical pain rating scale and the Western Ontario and McMaster Universities Osteoarthritis Index showed non-inferiority of the study to control group. Improvement in quadriceps strength was significantly greater in the study than in control group. Adverse events were not significantly different between groups. Most subjects were satisfied and rated themselves as improved or much improved. Approximately three-quarters of participants attended more than 20 sessions, and there was no significant difference in outcomes between good and poor compliance. Conclusion Pneumatic partial weight support treadmill can significantly decrease pain non-inferior to UTM, and can significantly increase quadriceps strength compared to UTM.

A Comparative Study of Effect of Forward vs Backward Walking on Quadriceps Strength Among College Students in Banglore

Background and purpose This study compared the effect of forward walking and backward walking on many aspects including kinematics kinetics and muscle activity.Methods Thirty subjects participated in this randomized clinical trial. The outcome measure used was Micro Force Evaluation and Testing FET2 Dynamometer for measuring quadriceps strength.Results The results were analyzed using the statistical software SPSS 21.0 version both descriptive and inferential analyses were used.Conclusion The study concludes that clinically backward walking can lead to higher quadriceps strength but statistically both forward and backward walking can increase quadriceps strength.

Development of reference charts for monitoring quadriceps strength with handheld dynamometry after total knee arthroplasty

Purpose: To develop reference charts that describe normative quadriceps strength recovery after total knee arthroplasty (TKA) as measured by handheld dynamometry (HHD). Materials and Methods: We conducted a retrospective analysis of post-TKA quadriceps strength recovery in a longitudinal dataset consisting of both clinical and research HHD data. We created sex-specific models for recovery using Generalized Additive Models for Location, Scale, and Shape. We created reference charts from the models to display the recovery of population centiles over the first six postoperative months. Results: A total of 588 patient records with 1176 observations were analyzed. Reference charts for both sexes demonstrated a rapid increase in quadriceps strength over the first 60 postoperative days followed by a more gradual increase over the next 120 days. Males appeared to demonstrate faster recovery and greater strength on average compared to females. The quadriceps strength recovery of three female patient records was plotted on the reference chart to illustrate the charts’ potential clinical utility. Conclusions: These reference charts provide normative data for quadriceps strength recovery after TKA as assessed by HHD. The reference charts may augment clinicians’ ability to monitor and intervene upon quadriceps weakness—a pronounced and debilitating post-TKA impairment—throughout rehabilitation. Implications for Rehabilitation Handheld dynamometry (HHD) is an objective and clinically feasible method for assessing muscle strength, but normative HHD values are lacking for quadriceps strength recovery after total knee arthroplasty (TKA). We created sex-specific reference charts which provide normative quadriceps strength HHD values for the first 180 days after TKA. These reference charts may improve clinicians’ ability to monitor and intervene upon post-TKA quadriceps strength deficits.

Muscle strength gains after strengthening exercise explained by reductions in serum inflammation in women with knee osteoarthritis

BackgroundIndividuals with knee osteoarthritis have elevated circulating inflammatory markers and altered cartilage properties but it is unclear if these features adapt to exercise. We aimed to determine (1) whether inflammatory markers, cartilage transverse relaxation time and thickness mediate the effect of body mass index (BMI) on quadriceps strength at baseline; and (2) whether these changes explain variance in quadriceps strength improvements after 12 weeks of exercise in women with knee osteoarthritis.MethodsThis secondary analysis (17 women with clinical knee osteoarthritis) of a randomized control trial compared supervised group interventions, 3 times/week for 12 weeks (36 sessions): (a) weight-bearing progressive resistive quadriceps exercise or (b) attention control. (1) From baseline, separate linear regressions were conducted with strength (Nm/kg) as the dependent, BMI as the predictor, and c-reactive protein, tumor necrosis factor, interleukin-6, cartilage transverse relaxation time or thickness as potential mediators. (2) Multiple linear regression analyses were completed with 12-week strength change (post-pre) as the dependent, change in serum inflammatory markers and cartilage measurements as predictors, and age, BMI and adherence as covariates.Findings(1) At baseline, there was no mediation. (2) A decrease in each of interleukin-6 (β = −0.104 (95% confidence intervals: −0.172, −0.036), R2 = 0.51, P < 0.007) and tumor necrosis factor (β = −0.024 (−0.038, −0.009), R2 = 0.54, P < 0.005) was associated with strength gains.InterpretationAt baseline, inflammatory markers and cartilage measurements do not act as mediators of BMI on quadriceps strength. After 12 weeks of exercise, reduced interleukin-6 and tumor necrosis factor were associated with increased quadriceps strength in women with knee osteoarthritis.

Effects of Whole-Body Vibration Therapy on Quadriceps Function in Patients With Anterior Cruciate Ligament Reconstruction: A Systematic Review.

Quadriceps dysfunction is common for patients after anterior cruciate ligament reconstruction (ACLR). Whole-body vibration (WBV) could effectively treat quadriceps dysfunction. To summarize WBV protocols for patients with ACLR and to evaluate the effects of WBV on quadriceps function. PubMed, CINAHL, SportDiscus, Web of Science, Medline, and Embase were searched from inception to January 2020. Randomized controlled trials recruiting patients with ACLR, using WBV as intervention, and reporting at least 1 of the following outcomes, strength, rate of torque development (RTD), and voluntary activation ratio of quadriceps, were included. Systematic review. Level 3. This systematic review was reported according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Quality of evidence was determined by PEDro criteria and GRADE system. Participant characteristics, interventions, and the relevant results of the included studies were extracted and synthesized in a narrative way. In total, 8 studies were included. Of these, 2 studies had serious risk of bias. Five of 8 studies implemented a series of WBV program ranging from 2 to 10 weeks in duration, while the other 3 studies implemented a single session of WBV. Eight WBV protocols were reported. The reported outcomes consisted of quadriceps strength, RTD, and central activation ratio. WBV protocols were heterogeneous. Low quality of evidence supported that exclusive conventional rehabilitation was more effective than exclusive WBV therapy in increasing quadriceps strength. Low quality of evidence supported that WBV combined with conventional rehabilitation was more beneficial in increasing quadriceps strength when compared with conventional rehabilitation alone. Very low quality of evidence supported the efficacy of a single session of WBV on quadriceps function. There is no standardized WBV protocol for patients with ACLR, and the effectiveness of WBV in rehabilitation on quadriceps function remains inconclusive.

Correlates of vastus medialis cross-sectional area in adults with symptomatic knee osteoarthritis

Purpose: Knee osteoarthritis is a common chronic joint disease affecting the whole joint. There is some evidence that increased quadriceps strength and muscle cross-sectional area (CSA) may help alleviate symptoms and slow disease progression, but the data is inconclusive. The aim of the study was to examine (1) the association between vastus medialis CSA and tibial cartilage volume cross-sectionally and longitudinally over 2 years, and (2) the association between vastus medialis CSA and knee pain and function cross-sectionally and longitudinally over 2 years, in individuals with symptomatic knee osteoarthritis.

Movement direction impacts knee joint kinematics during elliptical exercise at varying incline angles

BackgroundElliptical trainers are a popular cardiovascular exercise for individuals with injuries or those post-operation. There is currently limited data on the impacts of direction while on elliptical trainers for knee joint kinematic risk factors. This study compared lower extremity kinematics between the forward and reverse direction at varying inclines on an elliptical trainer modified with converging footpath and reduced inter-pedal distance. MethodsTwenty-four college age participants exercised on the modified elliptical in both directions at four ramp inclines: 6°, 12°, 25°, and 35°. Three-dimensional kinematics were collected for each direction and ramp incline. A 2 × 4 (direction × incline) repeated measures analysis of variance was run with an alpha of 0.05. Simple effects analysis was run with Bonferroni correction for significant interaction or main effect of ramp incline. ResultsThe reverse direction had significantly greater peak knee valgus at 6° incline (mean difference [MD] = 1.35°, p < 0.014, d = 0.31) and 12° (MD = 2.41°, p < 0.001, d = 0.55), peak hip abduction at 6° (MD = 2.86°, p = 0.002, d = 0.49) and 12° (MD = 2.91°, p < 0.001, d = 0.51), but decreased peak knee flexion angles (p = 0.032) at all inclines. ConclusionsIndividuals with knee pathologies such as knee osteoarthritis or anterior knee pain should exercise in the reverse direction at lower inclines. However, switching to the forward direction and/or increasing incline may increase quadriceps strength during a safe activity such as elliptical trainers.

Comparison of Blood Flow Restriction Training versus Non-Occlusive Training in Patients with Anterior Cruciate Ligament Reconstruction or Knee Osteoarthritis: A Systematic Review.

Patients undergoing anterior cruciate ligament (ACL) reconstruction and patients suffering from knee osteoarthritis (KOA) have been shown to have quadriceps muscle weakness and/or atrophy in common. The physiological mechanisms of blood flow restriction (BFR) training could facilitate muscle hypertrophy. The purpose of this systematic review is to investigate the effects of BFR training on quadriceps cross-sectional area (CSA), pain perception, function and quality of life on these patients compared to a non-BFR training. A literature research was performed using Web of Science, PEDro, Scopus, MEDLINE, Dialnet, CINAHL and The Cochrane Library databases. The main inclusion criteria were that papers were English or Spanish language reports of randomized controlled trials involving patients with ACL reconstruction or suffering from KOA. The initial research identified 159 publications from all databases; 10 articles were finally included. The search was conducted from April to June 2020. Four of these studies found a significant improvement in strength. A significant increase in CSA was found in two studies. Pain significantly improved in four studies and only one study showed a significant improvement in functionality/quality of life. Low-load training with BFR may be an effective option treatment for increasing quadriceps strength and CSA, but more research is needed.

Quadriceps muscle strength in Duchenne muscular dystrophy and effect of corticosteroid treatment.

ObjectivesIn Duchenne muscular dystrophy, quadriceps weakness is recognized as a key factor in gait deterioration. The objective of this work was three-fold: first, to document the strength of the quadriceps in corticosteroid-naïve DMD boys; second, to measure the effect of corticosteroids on quadriceps strength; and third, to evaluate the correlation between baseline quadriceps strength and the age when starting corticosteroids with the loss of ambulation.MethodsQuadriceps muscle strength using hand-held dynamometry was measured in 12 ambulant DMD boys who had never taken corticosteroids and during corticosteroid treatment until the loss of ambulation.ResultsBaseline quadriceps muscle strength at 6 years of age was 28% that of normal children of the same age; it decreased to 15% at 8 years and to 6% at 10 years. The increase in quadriceps muscle strength obtained after 1 year of corticosteroid treatment had a strong direct correlation with the baseline strength (R = 0.96). With corticosteroid treatment, the age of ambulation loss showed a very strong direct relationship (R = 0.92) with baseline quadriceps muscle strength but only a very weak inverse relationship (R = -0.73) with the age of starting treatment. Age of loss of ambulation was 10.3 ± 0.5 vs 19.1 ± 4.7 (P < 0.05) in children with baseline quadriceps muscle strength less than or greater than 40 N, respectively.ConclusionsCorticosteroid-naïve DMD boys have a quantifiable severe progressive quadriceps weakness. This long-term study, for the first time, shows that both of the positive effects obtained with CS treatment, i.e. increasing quadriceps strength and delaying the loss of ambulation, have a strong and direct correlation with baseline quadriceps muscle strength. As such, hand-held dynamometry may be a useful tool in the routine physical examination and during clinical trial assessment.

The associations of phase angle with the structural severity and quadriceps strength among patients with hip osteoarthritis: the SPSS-OK study.

This study examined whether phase angle (PhA) is associated with hip osteoarthritis (HOA) severity and quadriceps strength in patients with HOA. A series of 549 patients with HOA, obtained from the Screening for People Suffering Sarcopenia in the Orthopedic cohort of Kobe study, were analyzed. PhA and quadriceps strength were measured using bioelectrical impedance analysis and a handheld dynamometer, respectively. The HOA severity was graded using the Kellgren-Lawrence radiographic scale. We estimated (1) mean differences in PhA by differences in HOA severity and (2) mean differences in quadriceps strength by differences in PhA using general linear models. The patients' mean age was 64.9 years, and 85% were women. A decreasing trend of PhA associated with increasing HOA severity was observed (P for trend < 0.001). PhA was statistically associated with a decrease in HOA grade 4 compared with that associated with HOA grade 1 (mean difference, - 0.40°; 95% confidence interval (CI), - 0.51° to - 0.30°). PhA per leg was associated with greater quadriceps strength per leg independent of age, sex, leg muscle mass, and HOA severity (mean difference per 1° increase, 3.80 Nm; 95% CI, 0.93 to 6.66). There was insufficient evidence of any difference in the association between PhA and quadriceps strength by HOA severity and sex (P for interaction = 0.07 and 0.06, respectively). PhA gradually decreased with increasing HOA severity, especially in patients with end-stage HOA. Paying close attention to PhA might provide a key to increasing quadriceps strength, regardless of HOA severity. Key Points • PhA gradually decreased with progression of HOA, particularly in patients with end-stage HOA. • PhA was positively associated with quadriceps strength, regardless of HOA severity. • PhA could be one of the indicators of quadriceps strength in patients with HOA.

Does Standard Physical Therapy Increase Quadriceps Strength in Chronically Ventilated Patients? A Pilot Study.

Physical therapy is standard care for mechanically ventilated patients, but there is no evidence, using nonvolitional, objective measurements, that physical therapy increases muscle strength in this population. The present study tested the hypothesis that 2 weeks of standard, conventional physical therapy provided at a ventilator weaning facility would increase quadriceps strength in mechanically ventilated patients. Prospective observational study. Ventilator weaning unit. Patients who were transferred from an acute care hospital because of failure to wean from mechanical ventilation and who were receiving physical therapy as prescribed by facility staff. None. We employed a novel, nonvolitional objective technique, quadriceps twitch force generation in response to femoral nerve magnetic stimulation, to assess leg strength before and after 2 weeks of conventional physical therapy. The duration and specific exercises provided to patients were also recorded. In a subset of patients, we measured muscle activation intensity using wireless electromyogram recordings. Indices of respiratory function (maximum inspiratory pressure generation and the rapid shallow breathing index) were also assessed. Patients' responses to 2 weeks of physical therapy were poor; on average, quadriceps twitch fell by -1.02 ± 0.71 Newtons. Neither physical therapy duration nor specific forms of exercise were identified to positively impact quadriceps twitch. Electromyogram recordings indicated that during training, muscle activation was poor. Consequently, therapists spent substantial time performing exercises that elicited little muscle activation. Physical therapy did not improve respiratory function. Standard physical therapy delivered in a ventilator weaning facility failed to improve quadriceps leg strength in a majority of mechanically ventilated patients. The fact that mechanically ventilated patients fail to achieve high levels of muscle activation during physical therapy provides a potential explanation as to why physical therapy may often be ineffective. We speculate that use of novel methods which increase muscle activation during exercise may improve responses of mechanically ventilated patients to physical therapy.

Neuromuscular Electrical Stimulation Use after Total Knee Arthroplasty Improves Early Return to Function: A Randomized Trial.

Neuromuscular electrical stimulation (NMES) has been reported as an effective method for quadriceps strengthening which could attenuate muscle loss in the early total knee arthroplasty (TKA) postoperative recovery period. The purpose of this randomized controlled trial was to test whether postoperative use of NMES on TKA patients results in increased quadriceps strength and ultimately improved functional outcomes. This randomized controlled clinical trial of 66 primary TKA patients was conducted at a large academic medical center. Patients were randomized 2:1 into treatment (NMES use, n = 44) or control arm (no NMES, n = 22). Patients who used the device for an average of 200 minutes/week or more (starting 1 week postoperative and continuing through week 12) were considered compliant. Baseline measurements and outcomes were recorded at 3, 6, and 12 weeks postoperatively, and included quadriceps strength, range of motion (ROM), resting pain, functional timed up and go (TUG), stair climb test, and knee injury and osteoarthritis outcome score (KOOS) and veterans rand 12-item health survey (VR-12) scores. Patients in the treatment arm (NMES use) experienced quadriceps strength gains over baseline at 3, 6, and 12 weeks following surgery, which were statistically significant compared with controls with quadriceps strength losses at 3 (p = 0.050) and 6 weeks (p = 0.015). The TUG improvements for patients treated with NMES showed significant improvements at 6 (p = 0.018) and 12 weeks (p = 0.003) postoperatively. Use of a home-based application-controlled NMES therapy system added to standard of care treatment showed statistically significant improvements in quadriceps strength and TUG following TKA, supporting a quicker return to function.

Structural severity, phase angle, and quadriceps strength among patients with knee osteoarthritis: the SPSS-OK study.

The associations between severity of knee osteoarthritis (KOA) and phase angle (PhA) and between PhA and quadriceps strength in patients with KOA are unclear. This study examined (1) whether the structural severity of KOA affects PhA and (2) whether PhA affects quadriceps strength in patients with KOA. Data of 1093 patients with KOA, obtained from Screening for People Suffering Sarcopenia in the Orthopedic cohort of Kobe study, were analyzed. PhA was determined by bioimpedance. Quadriceps strength was measured using a handheld dynamometer. Structural severity of KOA was determined using Kellgren-Lawrence radiographic grading scale. A series of general linear models were fitted to estimate the magnitude of differences in PhA by differences in KOA severity and quadriceps strength by differences in PhA. The mean age of the patients was 72.8years, and 78% were women. Increasing KOA severity was associated with decreasing PhA, especially in men. In women, only grade 4 KOA was associated with a decrease in PhA (P for interaction = 0.048). PhA per leg was positively associated with quadriceps strength per leg, independent of age, sex, leg muscle mass, pain, and KOA severity (mean difference per 1° increase = 7.54Nm, 95% confidence interval = 5.51-9.57Nm). The association between PhA and quadriceps strength differed neither by sex nor by KOA severity (P for interaction = 0.133 and 0.185, respectively). PhA decreased with increasing KOA severity, and increasing PhA was associated with increasing quadriceps strength. Clinicians should, therefore, evaluate PhA to assess quadriceps strength in patients with KOA. Key Points • PhA gradually decreased with increasing severity of KOA, especially in men. • Increasing PhA was associated with increasing quadriceps strength. • Clinicians should focus on increasing muscle mass and PhA.