Contribution of components of the quadriceps femoris muscle for producing external torque in patients with patellofemoral pain syndrome

IntroductionDifferent muscular activities of the quadriceps components for producing necessary torque may change in patients with patellofemoral pain syndrome (PFPS). The aim of the current study, therefore, was to assess the contribution of each component of the quadriceps femoris muscle for producing external torque in patients with PFPS.MethodTwelve females with PFPS (24.7 ± 2.3 years) and twelve healthy matched females (25.4 ± 2.4 years) performed three consecutive knee flexion and extension movements with maximum effort at 45°/s and 300°/s using a Biodex system 3 dynamometer. Simultaneously, electromyographic (EMG) activities of the vastus medialis oblique (VMO), RF (rectus femoris) and vastus lateralis (VL) muscles were recorded using a DataLog instrument. Standard multiple regressions were used to assess the ability of EMG activities of the VMO, RF and VL muscles to predict normalized quadriceps femoris isokinetic concentric and eccentric torques at 45°/s and 300°/s in the normal and patient groups.ResultsIn the normal group, the VL and the VMO were the good predictors of quadriceps concentric torque at 45°/s and 300°/s, respectively. The VL and the RF were the good predictors of quadriceps eccentric torque at 300°/s in the patient group. No other conditions showed a considerable prediction for quadriceps torque in the normal or patient group.ConclusionFemales with PFPS differ with normal females in terms of the contribution of each component of the quadriceps femoris for producing external torque. Training the VMO for concentric contraction at both high and low velocities should be included in the management of the patients with PFPS.     

Association of quadriceps angle with plantar pressure distribution,navicular height and calcaneo-tibial angle

ObjectiveThe aim of study was to analyze the association between Quadriceps Angle (QA) and plantar pressure, navicular height (NH), and calcaneo-tibial angle (CTA).MethodsA total of 64 volunteers (mean age: 22.25 ± 2.54 (range:19–33)) participated in this cross sectional study. EMED-m (Novel GmbH, Germany) electronic pedobarograph was employed for dynamic plantar pressure measurement using two step protocol. The angle between the vertical axis of calcaneus and the long axis of Achilles tendon for CTA. The height of navicular tubercle from the ground was measured while the subject was standing on both feet for NH. QA was measured while the subject was standing in a relaxed posture where both feet bearing equal weight.ResultsThere were significant negative correlations between QA and maximum force (MxF) under the 4th. metatarsal head (MH4). The QA was also significantly correlated with MxF and force-time integral (FTI) under the bigtoe (BT). FTI under the 3rd. metatarsal head (MH3), MH4 and 5th. metatarsal head (MH5) were significantly negatively correlated with QA. Pressure-time integral (PTI) under the MH4 and MH5 were found to be significantly negatively correlated with QA. A significant correlation was also found between QA and NH (p < 0.0001), whilst there was no correlation between QA and CTA. Regression analysis showed that NH was appeared as the major contributor for the QA (β = −0.49, p < 0.001) in the dynamic condition, followed by BT-FTI (β = 0.37, p < 0.001) and MH5-MxF (β = −0.21, p < 0.037).ConclusionThese findings may imply that the NH which can at least be controlled by appropriate shoe inserts may affect QA. This way, loading pattern of both plantar region and whole lower extremity may be altered.Level of evidenceLevel III, Diagnostic Study.     

Recruitment of fibre types and quadriceps muscle portions during repeated, intense knee-extensor exercise in humans

To investigate recruitment of slow-twitch (ST) and fast-twitch (FT) muscle fibres, as well as the involvement of the various quadriceps femoris muscle portions during repeated, intense, one-legged knee-extensor exercise, 12 healthy male subjects performed two 3-min exercise bouts at ~110% maximum thigh O₂ consumption (EX1 and EX2) separated by 6 min rest. Single-fibre metabolites were determined in successive muscle biopsies obtained from the vastus lateralis muscle (n=6) and intra-muscular temperatures were continuously measured at six quadriceps muscle sites (n=6). Creatine phosphate (CP) had decreased (P<0.05) by 27, 73 and 88% in ST fibres and 25, 71 and 89% in FT fibres after 15 and 180 s of EX1 and after 180 s of EX2, respectively. CP was below resting mean–1 SD in 15, 46, 84 and 100% of the ST fibres and 9, 48, 85 and 100% of the FT fibres at rest, after 15 and 180 s of EX1 and after 180 s of EX2, respectively. A significant muscle temperature increase (T_m) occurred within 2–4 s at all quadriceps muscle sites. T_m varied less than 10% between sites during EX1, but was 23% higher (P<0.05) in the vastus lateralis than in the rectus femoris muscle during EX2. T_m in the vastus lateralis was 101 and 109% of the mean quadriceps value during EX1 and EX2, respectively. We conclude that both fibre types and all quadriceps muscle portions are recruited at the onset of intense knee-extensor exercise, that essentially all quadriceps muscle fibres are activated during repeated intense exercise and that metabolic measurements in the vastus lateralis muscle provide a good indication of the whole-quadriceps muscle metabolism during repeated, intense, one-legged knee-extensor exercise.     

Eccentric and concentric torque-velocity characteristics of the quadriceps femoris in man

Summary The primary purpose of this investigation was to study the eccentric and concentric torque-velocity characteristics of the quadriceps femoris in man using a recently developed combined isometric, concentric and eccentric controlled velocity dynamometer (the SPARK System). A secondary purpose was to compare the method error associated with maximal voluntary concentric and eccentric torque output over a range of testing velocities. 21 males (21–32 years) performed on two separate days maximal voluntary isometric, concentric and eccentric contractions of the quadriceps femoris at 4 isokinetic lever arm velocities of 0° · s^–1 (isometric), 30° · s^–1 120° · s^–1 and 270° · s^–1. Eccentric peak torque and angle-specific torques (measured every 10° from 30° to 70°) did not significantly change from 0° · s^–1 to 270° · s^–1 (p>0.05) (with the exception of angle-specific 40° torque, which significantly increased;p<0.05). The mean method error was significantly higher for the eccentric tests (10.6%±1.6%) than for the concentric tests (8.1%±1.7%) (p<0.05). The mean method error decreased slightly with increasing concentric velocity (p>0.05), and increased slightly with increasing eccentric velocity (p>0.05). A tension restricting neural mechanism, if active during maximal eccentric contractions, could possibly account for the large difference seen between the present eccentric torque-velocity results and the classic results obtained from isolated animal muscle.     

Does a torn anterior cruciate ligament lead to change in the central nervous drive of the knee extensors?

Summary Integrated surface electromyograms of the three superficial parts of the quadriceps and isokinetic knee extensor maximum torque and power production were recorded simultaneously and at different angular velocities in both legs in 11 male subjects with unilateral tear of the anterior cruciate ligament. The cross-sectional area (CSA) of the thigh and its muscular components were measured by computerized tomography. The principal findings were a small but significant decrease in quadriceps CSA on the affected side; a decreased active, but not passive, range of movement; decreased mechanical output, whether or not corrected for differences in CSA; and decreased electrornyographic activity — particularly in rectus femoris. These findings suggest that the reason for the decreased maximum and total knee extensor performance seen in these patients is a change in knee joint receptor afferent inflow.     

Chronic neurogenic quadriceps amyotrophies

Summary Two cases of quadriceps amyotrophy, probably of chronic neurogenic origin are reported. Only the knee jerks were diminished, the calves hypertrophic, and the serum creatine kinase level very high in one case, and there were neurogenic electromyographic abnormalities in the quadriceps. In the first case, biopsy of the quadriceps muscle revealed a neurogenic origin with hyalinized hypertrophic fibres. CT scan showed abnormalities not only in the quadriceps but also in the sartorius, gracilis and gastrocnemius muscles. A second biopsy specimen from the gastrocnemius muscle showed histological findings similar to those of the quadriceps. In the second case, the EMG and biopsy findings suggested a myogenic origin, but 6 years later they were compatible with neurogenic atrophy. Differentiation from Becker dystrophy is very difficult in the first case and the second case is more a focal spinal amyotrophy. Further, in spite of their localization, the extension of the affected muscles changes the diagnosis. The same applies to chronic quadriceps amyotrophy in general, which cannot be regarded as an entity, but which suggests muscular dystrophy, spinal atrophy, polymyositis or a metabolic disorder. These cases can be compared with the four cases reported in the literature, which were regarded as a forme fruste of chronic spinal amyotrophy.     

Simultaneous bilateral versus unilateral tibial tubercle fractures

PurposeTibial tubercle/tuberosity fractures are rare injuries in young patients accounting for less than one percent of physeal fractures. Bilateral simultaneous fractures are even rarer, with only a few case reports in literature. The purpose of our study was to describe the largest case series of bilateral simultaneous tibial tuberosity avulsion fractures and compare it with unilateral fractures. We also wanted to compare our bilateral fractures case series with all the cases reported in the last 65 years.MethodsIRB approved retrospective study involving patients under age 18 years with tibial tuberosity avulsion fractures. Bilateral simultaneous fractures were compared to a unilateral group including demographic data, mechanism of injury, clinical exam findings, complication rates, and outcomes including return to function. Statistical analysis was performed using Mann-Whitney and Fisher Exact tests to compare the different groups.Results138 patients (131 males, 7 females) from a tertiary children’s hospital between 2012 and 2019 with tibial tuberosity avulsion fractures were included. 11 bilateral simultaneous fractures (BL Group) were identified and compared to age matched cohort from the 127 unilateral fracture patients (UL group). There was no significant difference found in BMI, height, weight, age, sex, mechanism of injury, return to functional range of motion, and return to sports between the groups. 7/11 (63%) of the patients in the BL group who sustained simultaneous fractures had to be home bound and could not attend school for an average of 8.3 weeks. There was a higher rate of complications in the BL group (63.3%) compared to the UL group (21.1%), which was statistically significant. The most common complications in the bilateral group were hardware removal and wound dehiscence.ConclusionThis first case series comparing unilateral versus bilateral simultaneous tibial tuberosity avulsion fractures suggests that the final outcomes of the two groups are similar, however it shows a significantly higher complication rate and hardware removal rate in the BL group. This study is also the first to highlight the significant initial morbidity in the BL fracture group with issues with regards to early mobility and loss of school-days. Keeping in mind the profound initial impact the bilateral injury poses to the patient; surgeons can possibly plan for rigid fixation for early mobilization to better prepare bilateral fracture patients for the early post-operative recovery process.     

“Quadriceps myopathy”: a clinical variant form of becker muscular dystrophy

Summary A 26-year-old male with quadriceps myopathy is presented. He had a family history and only the bilateral quadriceps were wasted, without symptomatic weakness. The specimen of the muscle biopsy showed typical myopathic features without inflammatory reactions. The patchy defect of muscular dystrophin was proved by immunohistochemical study. Dystrophin analysis revealed abnormal 380 kDa dystrophin. Gene deletion was proved at exon 45–48 of Xp21 without frameshift. This case was considered to be a clinical variant form of Becker muscular dystrophy.     

Ultrasound evaluation of the quadriceps muscles in pronated foot posture

ObjectiveThe main goal of this study was to investigate the size of all portions of the quadriceps muscles in individuals with pronated foot posture compared to normal foot posture using ultrasound imaging.DesignTwenty nine females with pronated foot posture and 29 age-, body weight-, body height-matched females with normal foot posture were recruited from university communities. The muscle thicknesses of the rectus femoris (RF), vastus medialis (VM), vastus medialis oblique (VMO), vastus lateralis (VL) and vastus intermedius (VI) were measured using ultrasound imaging.ResultsThe thicknesses of the RF and VMO were significantly smaller in individuals with pronated foot posture compared to normal foot posture (p < 0.05). No significant differences were observed in the VM, VL, and VI muscle thicknesses in both groups.ConclusionBased on the results of the present study, it seems that besides the foot and lower leg muscles, an integrated assessment of proximal knee muscles, especially quadriceps, is required in individuals with pronated foot posture.