An investigation of lower limb joint powers as a predictive measure of countermovement vertical jump height.

Measuring and tracking athletic performance is crucial to an athlete’s development and the countermovement vertical jump is often used to measure athletic performance, particularly lower limb power. The linear power developed in the lower limb is estimated through jump height. However, the relationship between angular power, produced by the joints of the lower limb, and jump height is not well understood. This study examined the contributions of the kinetic value of angular power, and its kinematic component, angular velocity, of the lower limb joints to jump height in the countermovement vertical jump. Kinematic and kinetic data were gathered from twenty varsity-level basketball and volleyball athletes as they performed six maximal effort jumps in four arm swing conditions: no-arm involvement, single-non-dominant arm swing, single-dominant arm swing, and two-arm swing. The displacement of the whole body centre of mass, peak joint powers, peak angular velocity, and locations of the peaks as a percentage of the jump’s takeoff period, were computed. Linear regressions assessed the relationship of the variables to jump height. Results demonstrated that knee peak power (p = 0.001, ß = 0.363, r = 0.363), its location within takeoff period (p = 0.023, ß = -0.256, r = 0.256), and peak knee peak angular velocity (p = 0.005, ß = 0.310, r = 0.310) were moderately linked to increased jump height. Additionally, the location, within the takeoff period, of the peak angular velocities of the hip (p = 0.003, ß = -0.318, r = 0.419) and ankle (p = 0.011, ß = 0.270, r = 0.419) were positively linked to jump height. These results highlight the importance of training the velocity and timing of joint motion beyond traditional power training protocols as well as the importance of further investigation into appropriate testing protocol that is sensitive to the contributions by individual joints in maximal effort jumping.

Task-oriented training and lower limb strengthening to improve balance and function after stroke: a pilot study

This study investigated the effects of task-oriented training and strengthening of the affected lower limb on balance and function in people who have suffered a stroke. Sixteen male adults, with a mean age of 58 (SD 6.3) years, undergoing outpatient physiotherapy less than 1 month after a single stroke in the territory of the middle cerebral artery were recruited. Participants were allocated to one of two groups: the strengthening group (SG) or control group (CG). The main measures used were the Berg Balance Scale (BBS), Barthel Index (BI) and Modified Ashworth Scale (MAS). After 12 weeks of intervention, both groups showed improvements in outcome measures. For BBS, there was a significant difference between groups, with an increase of 26 points in the SG and 11 points in the CG. For BI, the SG improved by 39 points and the CG improved by 22 points. After intervention, the difference between groups was not significant. For MAS, differences were not significant, showing that for both groups intervention programmes did not increase spasticity. In conclusion, physiotherapy intervention for postural control dysfunctions after stroke seems to benefit from strength training of the affected lower limb and the practising functional tasks. A large randomized controlled trial is recommended to further investigate the effects of this intervention.

A randomised controlled trial comparing the effect of adjuvant intrathecal 2 mg midazolam to 20 micrograms fentanyl on postoperative pain for patients undergoing lower limb orthopaedic surgery under spinal anaesthesia.

Background: Intrathecal adjuvants are added to local anaesthetics to improve the quality of neuraxial blockade and prolong the duration of analgesia during spinal anaesthesia. Used intrathecally, fentanyl improves the quality of spinal blockade as compared to plain bupivacaine and confers a short duration of post-operative analgesia. Intrathecal midazolam as an adjuvant has been used and shown to improve the quality of spinal anaesthesia and prolong the duration of post-operative analgesia. No studies have been done comparing intrathecal fentanyl with bupivacaine and intrathecal 2 mg midazolam with bupivacaine. Objective: To compare the effect of intrathecal 2 mg midazolam to intrathecal 20 micrograms fentanyl when added to 2.6 ml of 0.5% hyperbaric bupivacaine, on post-operative pain, in patients undergoing lower limb orthopaedic surgery under spinal anaesthesia. Methods: A total of 40 patients undergoing lower limb orthopaedic surgery under spinal anaesthesia were randomized to two groups. Group 1: 2.6mls 0.5% hyperbaric bupivacaine with 0.4mls (20micrograms) fentanyl Group 2: 2.6mls of 0.5% hyperbaric bupivacaine with 0.4mls (2mg) midazolam Results: The duration of effective analgesia was longer in the midazolam group (384.05 minutes) as compared to the fentanyl group (342.6 minutes). There was no significant difference (P 0.4047). The time to onset was significantly longer in midazolam group 17.1 minutes as compared to the fentanyl group 13.2 minutes (P 0.023). The visual analogue score at rescue was significantly lower in the midazolam group (5.55) as compared to the fentanyl group 6.35 (P - 0.043). Conclusion: On the basis of the results of this study, there was no significant difference in the duration of effective analgesia between adjuvant intrathecal 2 mg midazolam as compared to intrathecal 20 micrograms fentanyl for patients undergoing lower limb orthopaedic surgery.

Lower limb and associated injuries in frontal-impact road traffic collisions.

Objectives: To study the relationship between severity of injury of the lower limb and severity of injury of the head, thoracic, and abdominal regions in frontal-impact road traffic collisions. Methods: Consecutive hospitalised trauma patients who were involved in a frontal road traffic collision were prospectively studied over 18 months. Patients with at least one Abbreviated Injury Scale (AIS) ≥3 or AIS 2 injuries within two AIS body regions were included. Patients were divided into two groups depending on the severity of injury to the head, chest or abdomen. Low severity group had an AIS < 2 and high severity group had an AIS ≥ 2. Backward likelihood logistic regression models were used to define significant factors affecting the severity of head, chest or abdominal injuries. Results: Eighty-five patients were studied. The backward likelihood logistic regression model defining independent factors affecting severity of head injuries was highly significant (p=0.01, nagelkerke r square = 0.1) severity of lower limb injuries was the only significant factor (p=0.013) having a negative correlation with head injury (Odds ratio of 0.64 (95% CI: 0.45-0.91). Conclusion: Occupants who sustain a greater severity of injury to the lower limb in a frontal-impact collision are likely to be spared from a greater severity of head injury.

Mobility and satisfaction with lower-limb prostheses and orthoses among users in Sierra Leone: A cross-sectional study

Objectives: To investigate patients' mobility and satisfaction with their lower-limb prosthetic or orthotic device and related service delivery in Sierra Leone; to compare groups of patients regarding type and level of assistive device, gender, area of residence, income; and to identify factors associated with satisfaction with the assistive device and service. Methods: A total of 139 patients answered questionnaires, including the Quebec User Evaluation of Satisfaction with Assistive Technology questionnaire (QUEST 2.0). Results: Eighty-six percent of assistive devices were in use, but half needed repair. Thirty-three percent of patients reported pain when using their assistive device. Patients had difficulties or could not walk at all on: uneven ground (65%); hills (75%); and stairs (66%). Patients were quite satisfied with their assistive device and the service (mean 3.7 out of 5 in QUEST), but reported 886 problems. Approximately half of the patients could not access services. In relation to mobility and service delivery, women, orthotic patients and patients using above-knee assistive devices had the poorest results. The general condition of the assistive device and patients' ability to walk on uneven ground were associated with satisfaction with the assistive devices and service. Conclusion: Patients reported high levels of mobility while using their device although they experienced pain and difficulties walking on challenging surfaces. Limitations in the effectiveness of assistive devices and limited access to follow-up services and repairs were issues desired to be addressed.

Literature review and update of lower limb neural mobilization

Summarize the available literature descriptions of neural mobilization (NM) techniques and neural provocation tests (NPT) for the Lower Limb (LL). Compilation of data was performed in May 2016 using MEDLINE data base, Google Scholar and the library of the European University of Madrid. After application of inclusion/exclusion criterions 5 books and 14 journal publications where found to be of interest and used during data extraction.Results: a list of 8 different LLNM techniques are applied in a rhythmic alternating oscillatory cycle fashion, starting in the initial position from where the therapist proceeds to move the limb in order to achieve a final position. LL NPTs are useful tools for differential diagnose and selecting the proper LLNM procedure. There is no consensus about the time frame of repetition intervals or amount of tensile strength during NPT never the less it is found to normally be performed at a rate of 2-4 seconds per complete cycle of movement, during 1-5 minutes, 3-5 times a week. LLNM treatment techniques all thou increasingly popular in clinical practice are found to be frugally described and lack proper standardization in regards to therapeutic dosification.

Objective analysis of gait coordination for total knee arthroplasty outcome

Introduction: Coordination is a strategy chosen by the central nervous system to control the movements and maintain stability during gait. Coordinated multi-joint movements require a complex interaction between nervous outputs, biomechanical constraints, and pro-prioception. Quantitatively understanding and modeling gait coordination still remain a challenge. Surgeons lack a way to model and appreciate the coordination of patients before and after surgery of the lower limbs. Patients alter their gait patterns and their kinematic synergies when they walk faster or slower than normal speed to maintain their stability and minimize the energy cost of locomotion. The goal of this study was to provide a dynamical system approach to quantitatively describe human gait coordination and apply it to patients before and after total knee arthroplasty. Methods: A new method of quantitative analysis of interjoint coordination during gait was designed, providing a general model to capture the whole dynamics and showing the kinematic synergies at various walking speeds. The proposed model imposed a relationship among lower limb joint angles (hips and knees) to parameterize the dynamics of locomotion of each individual. An integration of different analysis tools such as Harmonic analysis, Principal Component Analysis, and Artificial Neural Network helped overcome high-dimensionality, temporal dependence, and non-linear relationships of the gait patterns. Ten patients were studied using an ambulatory gait device (Physilog®). Each participant was asked to perform two walking trials of 30m long at 3 different speeds and to complete an EQ-5D questionnaire, a WOMAC and Knee Society Score. Lower limbs rotations were measured by four miniature angular rate sensors mounted respectively, on each shank and thigh. The outcomes of the eight patients undergoing total knee arthroplasty, recorded pre-operatively and post-operatively at 6 weeks, 3 months, 6 months and 1 year were compared to 2 age-matched healthy subjects. Results: The new method provided coordination scores at various walking speeds, ranged between 0 and 10. It determined the overall coordination of the lower limbs as well as the contribution of each joint to the total coordination. The difference between the pre-operative and post-operative coordination values were correlated with the improvements of the subjective outcome scores. Although the study group was small, the results showed a new way to objectively quantify gait coordination of patients undergoing total knee arthroplasty, using only portable body-fixed sensors. Conclusion: A new method for objective gait coordination analysis has been developed with very encouraging results regarding the objective outcome of lower limb surgery.

Total knee arthroplasty - a clinical and numerical study of the micromovements of the tibial implant

Introduction The importance of the micromovements in the mechanism of aseptic loosening is clinically difficult to evaluate. To complete the analysis of a series of total knee arthroplasties (TKA), we used a tridimensional numerical model to study the micromovements of the tibial implant.Material and Methods Fifty one patients (with 57 cemented Porous Coated Anatomic TKAs) were reviewed (mean follow-up 4.5 year). Radiolucency at the tibial bone-cement interface was sought on the AP radiographs and divided in 7 areas. The distribution of the radiolucency was then correlated with the axis of the lower limb as measured on the orthoradiograms.The tridimensional numerical model is based on the finite element method. It allowed the measurement of the cemented prosthetic tibial implant's displacements and the microvements generated at bone-ciment interface. A total load (2000 Newton) was applied at first vertically and asymetrically on the tibial plateau, thereby simulating an axial deviation of the lower limbs. The vector's posterior inclination then permitted the addition of a tangential component to the axial load. This type of effort is generated by complex biomechanical phenomena such as knee flexion.Results 81 per cent of the 57 knees had a radiolucent line of at least 1 mm, at one or more of the tibial cement-epiphysis jonctional areas. The distribution of these lucent lines showed that they came out more frequently at the periphery of the implant. The lucent lines appeared most often under the unloaded margin of the tibial plateau, when axial deviation of lower limbs was present.Numerical simulations showed that asymetrical loading on the tibial plateau induced a subsidence of the loaded margin (0-100 microns) and lifting off at the opposite border (0-70 microns). The postero-anterior tangential component induced an anterior displacement of the tibial implant (160-220 microns), and horizontal micromovements with non homogenous distribution at the bone-ciment interface (28-54 microns).Discussion Comparison of clinical and numerical results showed a relation between the development of radiolucent lines and the unloading of the tibial implant's margin. The deleterious effect of lower limbs' axial deviation is thereby proven. The irregular distribution of lucent lines under the tibial plateau was similar of the micromovements' repartition at the bone-cement interface when tangential forces were present. A causative relation between the two phenomenaes could not however be established.Numerical simulation is a truly useful method of study; it permits to calculate micromovements which are relative, non homogenous and of very low amplitude. However, comparative clinical studies remain as essential to ensure the credibility of results.

Bioimpedance for oedema evaluation after total knee arthroplasty.

BACKGROUND AND PURPOSE: Electrical bioimpedance spectroscopy (BIS) allows the evaluation of limb extracellular fluid (R0) and total fluid (Rinf). BIS could facilitate post-surgical oedema evaluation after total knee arthroplasty (TKA), as it is easily performed and is non-invasive. However, neither its applicability in this context nor the influence of metallic implants on measurement has been evaluated. The aim of this study was to evaluate the influence of TKA implants on the BIS R0 and Rinf variables used for oedema evaluation. METHOD: This was a prospective non-randomized comparative clinical trial. One oedema-free group of patients with TKA was compared with a group presenting similar characteristics except for the arthroplasty, to assess the influence of the implant on BIS measurement in the absence of oedema. The TKA group included 15 patients who had undergone surgery more than a year previously, and the control group included 19 patients awaiting TKA surgery. Volume and perimeter measurements served as reference criterions. The lower limb percentage differences for BIS, knee perimeter and volume were calculated. The significance of differences between groups was calculated for all measurement methods, using the Mann-Whitney test. The setting was a Department of Orthopedic Surgery and Traumatology in a university hospital. RESULTS: The differences between groups were not significant for R0, Rinf, volume and perimeter. R0 showed the smallest mean difference in limb percentage difference between groups [means (SD): TKA 3.98 (8.09), controls 3.97 (5.16)]. CONCLUSIONS: The lower-leg percentage difference in the TKA group is comparable with that of healthy subjects. R0 can be used for oedema evaluation following TKA surgery, as there was no sign of alteration from the metallic implant. These findings indicate the potential for early oedema evaluation after TKA. More research is warranted to extensively validate the application of BIS for oedema evaluation after TKA. Copyright © 2012 John Wiley & Sons, Ltd.

Objective results at 1 year of a new ultracongruent postero-stabilized total knee arthroplasty

Introduction: A new ultra congruent, postero-stabilized total knee arthroplasty (TKA) with a mobile bearing, the FIRST knee prosthesis (Free Insert in Rotation Stabilized in Translation, Symbios SA), was designed and expected to significantly reduce polyethylene wear, to improve the range of motion and the overall stability of the knee while ensuring a physiological ligament balance. Gait analysis has proven to give really objective outcome parameters after lower limb surgery. The goal of our study was to compare the subjective and really objective results of this new TKA with two other widespread models of TKA. Methods: A clinical prospective monocentric cohort study of 100 consecutive patients (47-88 yrs) undergoing a FIRST TKA for primary osteoarthritis is currently being done. Pre- and post-operative follow-ups (6 weeks, 4 months and 1 year) were done with well-recognized subjective evaluations (EQ-5D and WOMAC scores) and semi-objective questionnaires (KSS score and radiography evaluation) as well as with a really objective evaluation using gait parameters from 6 walking trials, performed at different speeds (slow, normal and fast) with an ambulatory gait analysis system (Physilog®, BioAGM CH). The outcomes of the first 32 new TKA after one year of follow-up were compared to the results after 1 year of a randomized controlled clinical trial comparing 29 NexGen® postero-stabilized TKA (Zimmer Inc) with a fixed bearing and 26 NexGen® TKA with a mobile bearing using the same methods. Results: Subjective and semi-objective results were similar for the three types of TKA. As for the really objective parameters, the gait cycle time of the FIRST TKA was statistically significantly shorter at normal speed of walk, as well as double-support periods, as compared to both standard models. The extension (in terms of range of motion when walking) of the operated knee was significantly improved for all three types of walk in favour of the FIRST TKAs compared to both NexGen TKAs. The normal walking speed was significantly higher with faster swing speed and stride lengths for the new TKA. Significantly better coordination scores were observed at normal walking speed for the FIRST TKA as compared to the fixed-bearing TKAs. Conclusion: The FIRST TKAs showed statistically significantly better objective outcomes in terms of gait after one year of follow-up with similar subjective and semi-objective results in comparison with widespread TKA designs. These encouraging short-terms results will have to be confirmed at a 5 years follow-up of the FIRST TKAs.

Effects of resistance training in older women with knee osteoarthritis and total knee arthroplasty

OBJECTIVES: This study sought to analyze the effects of resistance training on functional performance, lower-limb loading distribution and balance in older women with total knee arthroplasty (TKA) and osteoarthritis (OA) in the contralateral knee. In addition, this older knee OA and TKA group (OKG) was compared to older (OG) and young women (YG) without musculoskeletal diseases who underwent the same resistance training program.METHODS: Twenty-three women divided into OKG (N = 7), OG (N = 8) and YG (N = 8) had their functional performance, lower-limb loading distribution and balance compared before and after 13 weeks of a twice-weekly progressive resistance training program.RESULTS: At baseline, the OKG showed lower functional performance and unilateral balance, and impaired lower-limb loading distribution compared to the OG and the YG (p<0.05). After resistance training, the OKG showed improvements in functional performance (similar to 13% in sit-to-stand and rising from the floor, similar to 16% in stair-climbing and similar to 23% in 6-minute walking (6 MW)), unilateral balance (similar to 72% and,78% in TKA and OA leg, respectively) and lower-limb loading distribution, which were greater than those observed in the OG and the YG. The OKG showed post-training 6 MW performance similar to that of the OG at baseline. Sit-to-stand performance and unilateral stand balance were further restored to post-training levels of the OG and to baseline levels of the YG.CONCLUSIONS: Resistance training partially restored functional, balance and lower-limb loading deficits in older women with TKA and OA in the contralateral knee. These results suggest that resistance training may be an important tool to counteract mobility impairments commonly found in this population.

Males still have limb asymmetries in multijoint movement tasks more than 2 years following anterior cruciate ligament reconstruction

More than 2 years after undergoing anterior cruciate ligament (ACL) reconstruction, women still present bilateral asymmetries during multijoint movement tasks. Given the well-known ACL-injury gender bias, the goal of this study was to investigate whether males also present such asymmetries more than 2 years after undergoing ACL reconstruction. This study involved 12 participants submitted to ACL reconstruction in the ACL group and 17 healthy participants in the control group. The mean postoperative period was 37 months. The participants executed bilateral countermovement jumps and load squat tasks. The kinematics and ground reaction forces on each lower limb and pelvis were recorded, and used to compute bilateral peak vertical ground reaction forces, peak knee and hip joint powers in the sagittal plane, and the ratio between these powers. For the jump task, the groups had the same performance in the jump height, but for the ACL group the peak knee joint power on the operated side was 13% lower than on the non-operated side (p = 0.02). For the squat task, the hip-knee joint power ratio on the operated side of the ACL group was 31% greater than on the non-operated side (p = 0.02). The ACL group presented a deficit in the operated knee that had its energy generation over time (joint power) partially substituted by the hip joint power of the same side. The fact that, even after more than 2 years following the ACL reconstruction and returning to regular activity, the ACL group still had neuromuscular asymmetries suggests a need for improvement in the ACL reconstruction surgery procedures and/or rehabilitation protocols.