Passive Knee Flexion Research Articles

Acute effects of foam rolling on passive stiffness, stretch sensation, and fascial sliding: a randomized controlled trial

Abstract Purpose Foam Rolling (FR), aims to mimic the effects of manual therapy and tackle dysfunctions of the skeletal muscle and connective tissue. It has been shown to induce improvements in flexibility, but the underlying mechanisms are poorly understood. The aim of the present study was to further elucidate the acute, systemic and tissue-specific responses evoked by FR. Methods In a crossover study, 16 (34 ± 6y, 6f) participants received all of the following interventions in a random order: a) 2 × 60 seconds of FR at the anterior thigh, b) 2 × 60 seconds of passive static stretching of the anterior thigh (SS), and c) no intervention (CON). Maximal active and passive knee flexion range of motion (ROM), passive stiffness, sliding of fascial layers, as well as knee flexion angle of first subjectively perceived stretch sensation (FSS) were evaluated before and directly after each intervention. Results Flexibility increased only after, FR (active (+1.8 ± 1.9%) and passive ROM (+3.4 ± 2.7%), p = .006, respectively) and SS (passive ROM (+3.2 ± 3.5%), p = .002). Angle of FSS was altered following FR (+4.3° (95% CI: 1.4°–7.2°)) and SS (+6.7° (3.7°–9.6°)), while tissue stiffness remained unchanged after any intervention compared to baseline. Movement of the deepest layer (−5.7 mm (−11.3 mm to −0.1 mm)) as well as intrafascial sliding between deep and superficial layer (−4.9 mm (−9.mm to −0.7 mm)) decreased only after FR. Conclusion FR improved knee flexion ROM without altering passive stiffness, but modified the perception of stretch as well as the mobility of the deep layer of the fascia lata. The mechanisms leading to altered fascial sliding merit further investigation.

ACL Function in Bicruciate-Retaining Total Knee Arthroplasty.

Bicruciate-retaining total knee arthroplasty (BCR-TKA) is attracting attention because of the functional and satisfaction outcomes associated with keeping the anterior cruciate ligament (ACL) intact. However, knowledge of the functional importance of the ACL after BCR-TKA is limited. We performed a biomechanical investigation of ACL function following BCR-TKA compared with that in the intact knee. We investigated 8 fresh-frozen human cadaveric knees using a 6-degrees-of-freedom robotic system that allowed natural joint motion. Three knee states-intact knee, BCR-TKA, and BCR-TKA with ACL transection (BCR-TKA + ACLT)-were evaluated. For each knee state, the kinematics during passive flexion-extension motion (from 0° to 120°) and anteroposterior laxity at 0°, 15°, 30°, 60°, and 90° of flexion in response to a 100-N load were investigated. The recorded knee motions of the intact and BCR-TKA knees during each test were repeated after ACLT to calculate the ACL in situ force. The femur in the BCR-TKA group translated posteriorly and rotated externally during passive knee flexion and was in an anterior position compared with the femur in the intact-knee state. After ACLT, the femur translated posteriorly, compared with the BCR-TKA group, at 0° and 10° (p < 0.05). The anteroposterior laxities of the BCR-TKA and intact knees were comparable at all flexion angles and increased 2-fold or more after ACLT (p < 0.01). The ACL in situ force in the BCR-TKA knees was 2-fold to 6-fold higher than that in the intact knees at 0°, 15°, 90°, and 120° during a passive path (p < 0.05) and equivalent to that in the intact knees under anterior loading. The preserved ACL in the BCR-TKA knees was functional, like the ACL in the intact knees, under anterior tibial loading and contributed to good anteroposterior stability. However, the kinematics and ACL in situ force differed between the intact and BCR-TKA knees during passive flexion-extension movements. Surgeons may not be able to prevent overtensioning of the ACL during a standardized BCR-TKA procedure, which could potentially limit range of motion.

A Locked Intraosseous Nail for Transverse Patellar Fractures: A Biomechanical Comparison with Tension Band Wiring Through Cannulated Screws.

Displaced transverse patellar fractures require open reduction and internal fixation. State-of-the-art stabilization techniques are tension band wiring (TBW) using Kirschner wires or cannulated screws. These techniques are associated with high rates of secondary fracture displacement, implant migration, implant prominence, wound-healing disturbances, and the need for implant removal. Recently, a locked intraosseous patellar nail prototype was developed. The aim of the present study was to investigate the biomechanical performance of this nail compared with TBW using cannulated screws. Seven paired fresh-frozen human cadaveric knees were stripped of all soft tissues except the extensor apparatus. A transverse osteotomy was created to simulate an OTA/AO type 34-C1 transverse patellar fracture. The specimen pairs were randomly assigned to be fixed with TBW using cannulated screws or with the new intraosseous nail. Each specimen was cyclically tested for 5,000 cycles by pulling on the quadriceps tendon and simulating active knee extension and passive knee flexion within the range from 90° of flexion to full knee extension. Anterior and articular margin displacement of the fracture as well as interfragmentary rotation around the mediolateral axis were investigated with optical motion tracking after 100, 500, 1,000, 2,500, and 5,000 test cycles. Within the respective 5 testing-cycle time points evaluated, the articular margin displaced on average 68%, 60%, 72%, 76%, and 81% less after intraosseous nailing compared with TBW. Whereas the difference remained nonsignificant after 100 and 500 cycles (p ≥ 0.116), a trend toward significance was observed after 1,000 cycles (p = 0.063), which became significant after 2,500 and 5,000 cycles (p ≤ 0.043). From a biomechanical point of view, the locked intraosseous patellar nail may be an alternative to TBW using cannulated screws because of the higher interfragmentary stability provided at the articular fracture site. A locked patellar nail for transverse patellar fractures achieved a stable osteosynthetic construct that may reduce hardware-associated complications because of its intraosseous positioning.

The interaction of muscle moment arm, knee laxity, and torque in a multi-scale musculoskeletal model of the lower limb

IntroductionMusculoskeletal modeling allows insight into the interaction of muscle force and knee joint kinematics that cannot be measured in the laboratory. However, musculoskeletal models of the lower extremity commonly use simplified representations of the knee that may limit analyses of the interaction between muscle forces and joint kinematics. The goal of this research was to demonstrate how muscle forces alter knee kinematics and consequently muscle moment arms and joint torque in a musculoskeletal model of the lower limb that includes a deformable representation of the knee. MethodsTwo musculoskeletal models of the lower limb including specimen-specific articular geometries and ligament deformability at the knee were built in a finite element framework and calibrated to match mean isometric torque data collected from 12 healthy subjects. Muscle moment arms were compared between simulations of passive knee flexion and maximum isometric knee extension and flexion. In addition, isometric torque results were compared with predictions using simplified knee models in which the deformability of the knee was removed and the kinematics at the joint were prescribed for all degrees of freedom. ResultsPeak isometric torque estimated with a deformable knee representation occurred between 45° and 60° in extension, and 45° in flexion. The maximum isometric flexion torques generated by the models with deformable ligaments were 14.6% and 17.9% larger than those generated by the models with prescribed kinematics; by contrast, the maximum isometric extension torques generated by the models were similar. The change in hamstrings moment arms during isometric flexion was greater than that of the quadriceps during isometric extension (a mean RMS difference of 9.8 mm compared to 2.9 mm, respectively). DiscussionThe large changes in the moment arms of the hamstrings, when activated in a model with deformable ligaments, resulted in changes to flexion torque. When simulating human motion, the inclusion of a deformable joint in a multi-scale musculoskeletal finite element model of the lower limb may preserve the realistic interaction of muscle force with knee kinematics and torque.

COMPARISON OF THREE DIFFERENT DENSITY TYPE FOAM ROLLERS ON KNEE RANGE OF MOTION AND PRESSURE PAIN THRESHOLD: A RANDOMIZED CONTROLLED TRIAL

Foam rolling is a popular form of roller massage. To date, no studies have examined the therapeutic effects of different density type rollers. Understanding the different densities may provide clinicians with the knowledge to accurately prescribe a particular foam roller and safely progress the client. The purpose of this study was to compare the immediate effects of three different density type foam rollers on prone passive knee flexion range of motion (ROM) and pressure pain thresholds (PPT) of the quadriceps musculature. Pretest, posttest randomized controlled trial. Thirty-six recreationally active adults were randomly allocated to one of three groups: soft density, medium density, and hard density foam roller. The intervention lasted a total of two minutes. Outcome measures included prone passive knee flexion ROM and PPT. Statistical analysis included parametric and non-parametric tests to measure changes among groups. Between group comparisons revealed no statistically significant differences between all three rollers for knee ROM (p=.78) and PPT (p=.37). Within group comparison for ROM revealed an 88 (p < 0.001) post-intervention increase for the medium and hard density rollers and a 78 (p < 0.001) increase for the soft density roller. For PPT, there was a post-intervention increase of 180 kPa (p < 0.001) for the medium density roller, 175 kPa (p < 0.001) for the soft density roller, and 151 kPa (p < 0.001) for the hard density roller. All three roller densities produced similar post-intervention effects on knee ROM and PPT. These observed changes may be due to a local mechanical and global neurophysiological response from the pressure applied by the roller. The client's pain perception may have an influence on treatment and preference for a specific foam roller. Clinicians may want to consider such factors when prescribing foam rolling as an intervention. 2C.

Oral Contraceptives Attenuate Metaboreflex in Young Women

BackgroundSkeletal muscle afferent feedback (group III/IV) increases mean arterial pressure (MAP) and heart rate (HR) during exercise. Evidence suggests that oral contraceptive (OC) use can increase resting blood pressure. The influence of OC on MAP and HR when activating group III/IV afferents is unclear.ObjectiveTo determine if women taking OCs have greater cardiovascular responses to activating group III/IV afferents and if phases of menstrual cycle influence this response.MethodsTwelve women (means ± SD; 24±2 yrs, 7 taking OCs) attended two identical experimental visits, once during early follicular (low estrogen, days 1–4, LE) and once during ovulation (high estrogen, days 10–14, HE). Visits included 1) 3 min of rest and 3 min of passive knee flexion (HUMAC Norm, CSMI, Stoughton, MA) to activate the mechanoreflex and 2) steady state cycling (5 min) with bilateral post exercise circulatory occlusion (PECO) (2 min) of the vastus lateralis to activate the metaboreflex. Continuous noninvasive blood pressure (Nexfin, Edward Lifesciences, Irvine, CA) and a 3 lead ECG (AD Instruments, Coloroado Springs, CO) measured MAP and HR, respectively.ResultsResting MAP was similar in women taking OC (90±4 mmHg) vs. no OC (87±8 mmHg, p=0.24). Mechanoreceptor activation did not increase MAP (OC: 90±6 mmHg and no OC: 88±8 mmHg) or HR (OC: 64±7 bpm and no OC: 67±12 bpm, p&lt;0.05) in either group. MAP and HR were similar in women during both LE and HE phases with mechanoreflex activation (p&gt;0.05). Metaboreflex activation increased MAP in women not taking OCs (steady state 95±23 mmHg vs. PECO 105±24 mmHg). On the other hand, MAP decreased with metaboreceptor activation in women taking OCs (steady state 94±12 mmHg vs. PECO 89±16 mmHg, p=0.032). Resting HR was greater in women not taking OCs (136±11 bpm) vs. OCs (107±32 bpm, p&lt;0.05). HR declined with metaboreflex activation in both OC and no OC group irrespective of LE and HE phase (p&lt;0.05).ConclusionsAlthough mechanoreflex activation did not influence MAP for either group of women, women taking OCs had an attenuated MAP with metaboreflex activation. This is in contrast to evidence suggesting that OCs can increase MAP at rest and may indicate that during exercise OC use can be beneficial in lowering blood pressure in women.Support or Funding InformationNo funding to disclose.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Rectus Femoris Transfer Versus Rectus Intramuscular Lengthening for the Treatment of Stiff Knee Gait in Children With Cerebral Palsy.

Rectus femoris transfer (RFT) is used to treat stiff knee gait in spastic cerebral palsy. Recently, rectus femoris lengthening has been reported as treatment for stiff knee gait. The purpose of this study was to compare short-term outcomes of 2 surgical procedures. A retrospective chart review of 23 patients (42 limbs) with diplegic spastic cerebral palsy who had undergone rectus femoris intramuscular lengthening for treatment of stiff knee gait with a Gross Motor Function Classification System level I, II, or III was completed. These patients were matched with a cohort of 23 patients (42 limbs) who had undergone RFTs based on age, sex, Gross Motor Function Classification System level, diagnosis, preoperative Gait Deviation Index, and any simultaneous surgeries. Preoperative and 1 year postoperative motion analysis data and physical examination were compared. There were no significant differences in demographics between the groups. On physical examination, a positive postoperative Duncan-Ely test was seen significantly less often in the transfer limbs (20 vs. 37). Average postoperative quad tone score was 1.56 for the transfer group compared with 2.19 for the lengthening group. No significant postoperative difference was seen between groups in stride length, walking speed, cadence, knee flexion at initial contact, peak knee flexion during loading response, mean knee flexion in stance, peak knee flexion in swing, time to peak knee flexion (% swing), time to peak knee flexion (% gait cycle), Gait Deviation Index or total knee range of motion. There was a difference in time to achieve 90 degrees passive knee flexion with the lengthening group reaching this in 8.3 days and transfer group in 15.3 days (P<0.0001). Motion analysis parameters showed results of RFT and rectus femoris intramuscular lengthening to be equivalent 1 year postoperatively. Since rectus femoris lengthening is technically less difficult and rehabilitation faster, rectus femoris lengthening may be preferred if long-term follow-up supports these findings. Level III-retrospective comparative study.

Native rotational knee kinematics is restored after lateral UKA but not after medial UKA.

The aim of this study was to compare the intraoperative kinematics of medial and lateral unicompartmental knee arthroplasty (UKA) with those of the native knee using a navigation system. Six fresh-frozen cadaveric knees were included in the study. Medial UKA was performed in all right knees and lateral UKA was performed in all left knees. All UKA procedures were performed with a computerised navigation system. The tibial internal rotation angle and coronal alignment of the mechanical axis during passive knee flexion were assessed as rotational and varus/valgus kinematics before and after surgery using the navigation system. The rotation angles of the tibia in the early flexion phase of medial UKA were significantly larger than those of native knees (p = 0.008at minimum knee flexion, p = 0.008at 0° knee flexion). The rotational kinematics of lateral UKA was similar to those of the native knees throughout knee flexion. There were no significant differences in varus/valgus kinematics between native and UKA knees. The rotational kinematics of the native knee was not restored after medial UKA but was preserved after lateral UKA. There were no significant differences in the varus/valgus kinematics after either medial or lateral UKA when compared with those of the native knees. Thus, the geometry of the medial tibial articular surface is a determinant of the ability to restore the rotational kinematics of the native knee. Surgeons and implant designers should be aware that the anatomical medial articular geometry is an important factor in restoration of the native knee kinematics after knee arthroplasty.

Local infiltration analgesia combined with a standardized multimodal approach including an adductor canal block in total knee arthroplasty: a prospective randomized, placebo-controlled, double-blinded clinical trial

Total knee arthroplasty (TKA) is associated with moderate to severe postoperative pain. This study evaluates the technique of local infiltration analgesia (LIA), by comparing it to saline injections in addition to a standardized multimodal regimen including an adductor canal block. Between September 2015 and March 2016, forty patients aged 18years and older, ASA I-III, undergoing primary unilateral cemented TKA under spinal anesthesia were randomized to receive either LIA (LIA group) or normal saline (sham LIA group). Morphine consumption during the first 24 postoperative hours, time to first IV morphine dose request, pain intensity at rest and passive knee flexion, complication rates, patient satisfaction and duration of hospitalization were documented (Clinicaltrials.gov, identifier: NCT03206554). Compared with the sham LIA group, the LIA group showed statistically significant lower morphine consumption at all times (6, 12, 18, 24h-P value: 0.035, 0.008, 0.015 and 0.003, respectively). Time to first IV morphine dose request did not differ significantly between groups (P = 0.902). The intergroup difference in NRS pain scores was statistically significant, with the LIA group showing lower resting and dynamic pain scores in all instances and additionally higher patient satisfaction. The groups did not differ in terms of complication rates and duration of hospitalization. Performing LIA in addition to a standardized multimodal analgesia regimen results in superior pain control, demonstrated as reduced opioid needs and lower resting and dynamic pain intensity scores on the first postoperative day after TKA. Further studies are needed to establish an LIA protocol that could maximize postoperative pain control.

Fixed-bearing medial unicompartmental knee arthroplasty restores neither the medial pivoting behavior nor the ligament forces of the intact knee in passive flexion.

Medial unicompartmental knee arthroplasty (UKA) is an accepted treatment for isolated medial osteoarthritis. However, using an improper thickness for the tibial component may contribute to early failure of the prosthesis or disease progression in the unreplaced lateral compartment. Little is known of the effect of insert thickness on both knee kinematics and ligament forces. Therefore, a computational model of the tibiofemoral joint was used to determine how non-conforming, fixed bearing medial UKA affects tibiofemoral kinematics, and tension in the medial collateral ligament (MCL) and the anterior cruciate ligament (ACL) during passive knee flexion. Fixed bearing medial UKA could not maintain the medial pivoting that occurred in the intact knee from 0° to 30° of passive flexion. Abnormal anterior-posterior (AP) translations of the femoral condyles relative to the tibia delayed coupled internal tibial rotation, which occurred in the intact knee from 0° to 30° of flexion, but occurred from 30° to 90° of flexion following UKA. Increasing or decreasing tibial insert thickness following medial UKA also failed to restore the medial pivoting behavior of the intact knee despite modulating MCL and ACL forces. Reduced AP constraint in non-conforming medial UKA relative to the intact knee leads to abnormal condylar translations regardless of insert thickness even with intact cruciate and collateral ligaments. This finding suggests that the conformity of the medial compartment as driven by the medial meniscus and articular morphology plays an important role in controlling AP condylar translations in the intact tibiofemoral joint during passive flexion. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:1868-1875, 2018.

Comparison of a foam rolling session with active joint motion and without joint motion: A randomized controlled trial

BackgroundFoam rolling has become a popular form of self-myofascial release or roller massage among health and fitness professionals. Due to this popularity, foam roller devices can be found in many clinical and fitness settings. Despite the popularity, there are still several unknowns regarding foam rolling such the optimal technique. Specifically, there is a lack of research analyzing different foam roll techniques such as combining active joint motion with foam rolling. PurposeThe purpose of this study was to compare the effects of a foam rolling session to the left quadriceps with active joint motion and without joint motion on passive knee flexion range of motion (ROM) and pressure pain thresholds (PPT). MethodsThirty healthy adults were randomly allocated to one of two intervention groups: active joint motion and no joint motion. Each foam roll intervention to the left quadriceps lasted a total of 2 min. Dependent variables included passive knee flexion ROM and pressure pain threshold measures (PPT). Statistical analysis included subject demographic calculations and appropriate parametric and non-parametric tests to measure changes within and between intervention groups. ResultsFor left knee ROM, the active joint motion group demonstrated the greatest immediate increase in passive ROM (8°, p < .001) than the non-motion group (5°, p < .001). For PPT, the active joint motion group demonstrated the greatest immediate increase (180 kPa, p < .001) followed by the non-motion group (133 kPa, p < .001). Between group comparisons revealed a significance between groups for passive knee ROM (p < .001) and PPT (p < .001). ConclusionA short session of foam rolling with active joint motion appears to have a greater effect on passive joint ROM and PPT than rolling without motion. These observed changes may be influenced by the agonistic muscle activity during active motion. This activity may modulate activity of the antagonist muscle through reciprocal inhibition and other neural pathways. Future research is needed to confirm these findings.

Native rotational knee kinematics are lost in bicruciate-retaining total knee arthroplasty when the tibial component is replaced.

To compare the kinematics between native knees and knees that have undergone bicruciate-retaining (BCR) total knee arthroplasty (TKA) with cruciate-retaining (CR) TKA converted from BCR TKA in the same whole-body cadaveric specimen using a navigation system and, if differences exist, to investigate the point at which normal kinematics are lost during the procedure. The rotational kinematics throughout passive flexion of the native knee and of knees after meniscectomy, femoral replacement, BCR TKA, or CR TKA were assessed in nine fresh frozen cadavers using an image-free navigation system. The rotational kinematic pattern of a knee after BCR TKA was different from that of a native knee, especially in the early flexion phase, and was similar to that after CR TKA. Screw-home movement was not observed after BCR TKA, but still occurred after meniscectomy or femoral replacement with intact cruciate ligaments and an intact tibial articular surface. The rotational kinematics of the native knee are not always preserved after BCR TKA. Native rotational kinematics are preserved after meniscectomy and femoral replacement, but are lost after tibial replacement in BCR TKA. Surgeons should pay close attention to maintain the anteroposterior stabilizing function of the ACL in BCR TKA, rather than to restore the native rotational kinematics.

Changes in patellar tendon length during passive knee flexion in the menstrual cycle

Changes in patellar tendon length during passive knee flexion in the menstrual cycle

Heterogeneity of passive elastic properties within the quadriceps femoris muscle-tendon unit.

The purpose of this study was to compare regional elastic properties between anterior and posterior regions of the patellar tendon, and individual quadriceps muscles, over a range of knee flexion angles. An isokinetic dynamometer passively positioned the non-dominant knee of 19 young, healthy participants, at 25°, 40°, 55°, 70° and 85° flexion. Shear wave velocity (SWV, an index of tissue elasticity) was measured using ultrasound shear wave elastography in a relaxed (passive) state, confirmed by electromyography. SWV of the patellar tendon and quadriceps muscles increased with knee flexion (longer muscle-tendon unit; P < 0.001). Within the proximal third of the patellar tendon, SWV was lower in the posterior than anterior region at 70° (P = 0.002) and 85° (P < 0.001), but not at 25°, 40° or 55° (region-by-angle interaction, P = 0.007). No differences were found between anterior and posterior regions within the middle third of the patellar tendon (P = 0.332). For the quadriceps muscles, a significant muscle-by-angle (P < 0.001) interaction was also observed. SWV of VL was greater than VM at 55° (P = 0.005), 70° (P = 0.001) and 85° (P < 0.001), but not at 25° or 40°. SWV of RFwas lower than VL at all angles (all P < 0.002) and lower than VM at 55°, 70° and 85° (all P < 0.002). Passive knee flexion at and beyond 70° was associated with non-uniform elastic properties within the proximal patellar tendon and between individual quadriceps muscles. To what extent this heterogeneity of passive elastic properties contributes to injury remains unknown.

Diagnostic Validity of Combining History Elements and Physical Examination Tests for Traumatic and Degenerative Symptomatic Meniscal Tears

BackgroundThe current approach to the clinical diagnosis of traumatic and degenerative symptomatic meniscal tears (SMTs) proposes combining history elements and physical examination tests without systematic prescription of imaging investigations, yet the evidence to support this diagnostic approach is scarce. ObjectiveTo assess the validity of diagnostic clusters combining history elements and physical examination tests to diagnose or exclude traumatic and degenerative SMT compared with other knee disorders. DesignProspective diagnostic accuracy study. SettingsPatients were recruited from 2 orthopedic clinics, 2 family medicine clinics, and from a university community. PatientsA total of 279 consecutive patients who underwent consultation for a new knee complaint. MethodsEach patient was assessed independently by 2 evaluators. History elements and standardized physical examination tests performed by a physiotherapist were compared with the reference standard: an expert physicians’ composite diagnosis including a clinical examination and confirmatory magnetic resonance imaging. Participating expert physicians were orthopedic surgeons (n = 3) or sport medicine physicians (n = 2). Penalized logistic regression (least absolute shrinkage and selection operator) was used to identify history elements and physical examination tests associated with the diagnosis of SMT and recursive partitioning was used to develop diagnostic clusters. Main Outcome MeasuresDiagnostic accuracy measures were calculated including sensitivity, specificity, positive and negative predictive values, and positive and negative likelihood ratios (LR+/–) with associated 95% confidence intervals (CIs). ResultsEighty patients had a diagnosis of SMT (28.7%), including 35 traumatic tears and 45 degenerative tears. The combination a history of trauma during a pivot, medial knee pain location, and a positive medial joint line tenderness test was able to diagnose (LR+ = 8.9; 95% CI 6.1-13.1) or exclude (LR– = 0.10; 95% CI 0.03-0.28) a traumatic SMT. Combining a history of progressive onset of pain, medial knee pain location, pain while pivoting, absence of valgus or varus knee misalignment, or full passive knee flexion was able to moderately diagnose (LR+ = 6.4; 95% CI 4.0-10.4) or exclude (LR– = 0.10; 95% CI 0.03-0.31) a degenerative SMT. Internal validation estimates were slightly lower for all clusters but demonstrated positive LR superior to 5 and negative LR inferior to 0.2 indicating moderate shift in posttest probability. ConclusionDiagnostic clusters combining history elements and physical examination tests can support the differential diagnosis of SMT. These results represent the initial derivation of the clusters and external validation is mandatory. Level of EvidenceI

Reliability and Concurrent Validity of the Goniometer-Pro App vs a Universal Goniometer in determining Passive Flexion of Knee

Reliability and Concurrent Validity of the Goniometer-Pro App vs a Universal Goniometer in determining Passive Flexion of Knee

Monitoring the effect of football match congestion on hamstring strength and lower limb flexibility: Potential for secondary injury prevention?

ObjectivesTo investigate the effect of competitive football match congestion on hamstring strength and lower limb flexibility. DesignRepeated measures. SettingElite male youth football. ParticipantsFifteen male elite youth football players from the national football association centre of excellence were included (age = 15.81 ±0.65 years, height = 171.95 ±6.89 cm, weight = 65.93 ±7.53 kg). Main outcome measuresHamstring strength and pain, ankle dorsiflexion, hip extension, knee extension and flexion range of motion. ResultsHamstring strength was highest at baseline and significantly reduced at 24 (p = 0.001, mean difference −0.19 Nm/Kg, CI95 −0.28, −0.1) and 48 h post-match 1 (p = 0.002, mean difference −0.16 Nm/Kg, CI95 −0.25, −0.07). Strength recovered by match day 2 before significantly reducing again 24 h post-match 2 (p = 0.012, mean difference −0.17 Nm/Kg, CI95 −0.29, −0.04). Pain was lowest at baseline and increased in the post-match periods (p < 0.05) with standardised effect sizes ranging from 0.07 to 0.42. Passive knee flexion range decreased post-match (p < 0.01) with mean differences of 1.5°–2.7°. The other flexibility measures remained unaffected by match play. ConclusionIsometric hamstring strength and pain can be considered for inclusion in-season to monitor player's post-match hamstring recovery characteristics during congested match fixtures.

Nonuniform Deformation of the Patellar Tendon During Passive Knee Flexion.

The purpose of this study was to evaluate localized patterns of patellar tendon deformation during passive knee flexion. Ultrasound radiofrequency data were collected from the patellar tendons of 20 healthy young adults during knee flexion over a range of motion of 50°-90° of flexion. A speckle tracking approach was used to compute proximal and distal tendon displacements and elongations. Nonuniform tissue displacements were visible in the proximal tendon (P < .001), with the deep tendon undergoing more distal displacement than the superficial tendon. In the distal tendon, more uniform tendon motion was observed. Spatial variations in percent elongation were also observed, but these varied along the length of the tendon (P < .002), with the proximal tendon remaining fairly isometric while the distal tendon underwent slight elongation. These results suggest that even during passive flexion the tendon undergoes complex patterns of deformation. Proximal tendon nonuniformity may arise from its complex anatomy where the deep tendon inserts onto the patella and the superficial tendon extends to the quadriceps tendon. Such heterogeneity is not captured in whole tendon average assessments, emphasizing the relevance of considering localized tendon mechanics, which may be key to understanding tendon behavior and precursors to injury and disease.

Effect of continuous adductor canal or femoral nerve block on pain relief and early rehabilitation following total knee arthroplasty

Objective To compare the analgesic effect of continuous adductor canal block(ACB) and continuous femoral nerve block(FNB) after total knee arthroplasty(TKA). Methods Sixty patients scheduled for unilateral TKA were randomly assigned into two groups, receiving continuous ACB(group A) or continuous FNB(group F). Intravenous anesthesia was applied throughout the operation. The adductor canal and the femoral nerve were catheterized for block under the guidance of sonography before induction of general anesthesia. Patient-controlled analgesia was provided immediately after surgery with 0.2% ropivacaine through the perineural catheter. The pain severity at rest and upon movement (passive knee flexion of 45 degrees) with a 0-10 numeric rating scale (NRS), the Lovett score of muscle strength of the quadriceps femoris, and the modified Bromage score of the motor block of the affected extremity were assessed 4, 8, 12, 24, 48 h after surgery. The maximal range of active/passive motion of the knee joint was recorded 1, 2, 3, 14 d after surgery. The number of effective patient-controlled bolus of ropivacaine and the number of need for opioid rescue within 48 h after surgery, the first time of out-of-bed activity, the time of active knee flexion reaching 90 degrees, and the hospital for special surgery(HSS) score of knee function 14 d after surgery were also recorded. Results There was no difference between group A and group F in terms of the NRS scores at rest and upon movement, the number of effective patient-controlled bolus of ropivacaine and the number of need for opioid rescue (P>0.05). Patients in group A had a higher Lovett score of muscle strength of the quadriceps femoris and a lower modified Bromage score of the motor block than those in group F within 12 h after surgery (P 0.05). Conclusions An equal postoperative analgesic efficacy was observed in patients receiving continuous ACB and continuous FNB. Furthermore, continuous ACB did not provide a superior effect on early rehabilitation than continuous FNB. Key words: Adductor canal block; Femoral nerve block; Total knee arthroplasty; Postoperative analgesia; Rehabilitation

Posterior Cruciate Ligament Injuries Associated With Military Survival Swim Training.

Posterior cruciate ligament (PCL) injuries are relatively common injuries associated with athletic activities and high-energy trauma. Posterolateral corner (PLC) injuries frequently accompany injury to the PCL. Diagnosis can be challenging and requires a comprehensive history and physical examination. Patients frequently report vague, nonspecific symptoms and the mechanism of injury is often useful in localizing injured structures. Two of the more common mechanisms for PCL injury include a direct blow to the proximal anterior tibia with the knee flexed, as well as a significant knee hyperextension injury. With a PCL tear, patients rarely describe an audible "pop" that is commonly reported in ACL injuries. On physical exam, a frequent finding in PCL tears is a loss of 10 to 20° of knee flexion. Although the most common clinical tests for PCL tears include the posterior drawer test, the posterior sag sign, and the quadriceps active test, there is a lack of high-quality diagnostic accuracy studies. Two cases of U.S. Military Academy Cadets who sustained PCL injuries while removing combat boots during military survival swim training are presented. The results of the clinical examination are accompanied by magnetic resonance imaging results and intraoperative arthroscopic images to highlight key findings. Both patients were evaluated and diagnosed with PCL injures within 10 days of their injuries. Each reported feeling/hearing a "pop," which is atypical in PCL tears. Both patients demonstrated a lack of active and passive knee flexion, which is a commonly reported impairment. One patient was managed nonsurgically with physical therapy and eventually returned to full duty without limitations 9 months after his injury. The other patient, who sustained a combined PCL-PLC injury, underwent a PCL reconstruction and PLC repair and reconstruction 8 weeks after his injury. He returned all training, with the exception of contact/collision sports, 9 months after surgery. Both patient's rehabilitation programs consisted of a progression of exercises to improve range of motion, muscle strength/endurance, motor control, and muscular power. Military and sports medicine professionals should be aware of the potential for PCL injury with this unusual, and previously unreported, mechanism of injury during survival swim training. Prompt diagnosis and appropriate treatment is essential to prevent long-term disability.