Gait and strength assessment following surgical repair by intramedullary nailing of isolated tibial shaft fracture.

The objective of the study was to evaluate the long-term strength and gait outcomes after intramedullary nailing of isolated tibial diaphyseal fractures. This retrospective cohort study was conducted at an academic Level I trauma center. Fifteen participants with isolated tibial diaphyseal fractures (OTA/AO 42) at least 2 years postoperative from intramedullary nailing (IMN) provided informed consent. The average age was 40 ± 14 (range, 24-69); there were nine men and six women. Knee flexion-extension strength data were collected. Temporal-spatial, kinematic, and kinetic gait parameters were measured and compared to historic control data. Participants completed the SF-36 and shortened musculoskeletal function assessment questionnaires. The mean length of follow-up between surgery and gait analysis was 6 ± 2 years. The fractured limb demonstrated deficits in quadriceps strength between 9.8% and 23.4% compared to the unaffected limb. Temporal-spatial parameters revealed slower walking speed, shorter stride length, decreased cadence, and shorter single-limb support time in the fractured limb. Altered kinematic and kinetic findings included a knee extension shift during stance, with an increased knee flexor moment demand and decreased total knee power during loading and midstance. These findings represent deficits in concentric and eccentric knee extensor activity. Additionally, the fractured limb demonstrated decreased ankle dorsiflexion during stance and diminished ankle push-off power. Long-term outcomes after IMN of tibial diaphyseal fractures demonstrate decreased quadriceps strength and altered gait parameters that may have implications to the high incidence of knee and ankle pain in the fractured limb.

Impact of Internal Malrotation of the Femur Followed by Derotational Osteotomy as Demonstrated by 3D Gait Analysis: A Case Report.

CASE: An 18-year-old man with 48° of internal malrotation of the femur after nailing underwent derotational osteotomy with gait dynamics and electromyography data collected preoperatively and postoperatively. Hip abduction and internal foot progression angles were significantly deviated from normal preoperatively compared with the contralateral side. At 10 months postoperatively, the hip was abducted and externally rotated throughout the entire gait cycle. His Trendelenburg gait had resolved, and he reported no residual functional concerns. Before corrective osteotomy, walking velocity was significantly slower with shorter stride lengths. CONCLUSION: Significant internal malrotation of the femur impairs hip abduction and foot progression angles as well as gluteus medius activation during ambulation. Derotational osteotomy considerably corrected these values.

Multi-segment foot kinematics during gait following ankle arthroplasty.

Ankle arthritis is a debilitating disease marked by pain and limited function. Total ankle arthroplasty improves pain while preserving motion and offers an alternative to the traditional treatment of ankle fusion. Gait analysis and functional outcomes tools can provide an objective balanced analysis of ankle replacement for the treatment of ankle arthritis. Twenty-nine patients with end-stage ankle arthritis were evaluated before and after ankle arthroplasty. Multi-segment foot and ankle kinematics were assessed annually following surgery (average 3.5 years, range 1-6 years) using the Milwaukee Foot Model and a Vicon video motion analysis system. Functional outcomes (American Orthopedic Foot and Ankle Society [AOFAS] ankle/hindfoot scale, short form 36 [SF-36] questionnaire) and temporal-spatial parameters were also assessed. Kinematic results were compared to findings from a previously collected group of healthy ambulators. AOFAS and SF-36 mean scores improved postoperatively. Walking speed and stride length increased after surgery. There were significant improvements in tibial sagittal range of motion in terminal stance and hindfoot sagittal range of motion in preswing. Decreased external rotation of the tibia and increased external rotation of the hindfoot were noted throughout the gait cycle. Pain and function improved after ankle replacement as supported by better outcomes scores, increased temporal-spatial parameters, and significant improvement in tibial sagittal range of motion during terminal stance and hindfoot sagittal range of motion during preswing. While multi-segment foot kinematics were improved, they were not restored to control values. Statement of clinical significance: Total ankle arthroplasty does not fully normalize mutli-segment gait kinematics despite improved patient-reported outcomes and gait mechanics.

Inverse Kinematic Assessment of Rehabilitative Therapy in Children Using Orthotics.

Pathologic movement patterns are characterized by abnormal kinematics that alter how muscles support the body during walking. Individual muscles are often the target of interventions with physical therapy and surgery alike, yet the tools to assess individual muscles clinically remain limited. The aim of this study is to assess OpenSim as a clinical tool for individualized rehabilitative evaluation of children using orthotics. This anatomic and kinematic modeling study was focused on pre- and post-treatment assessment of gait characteristics in fourteen children using orthotic devices. A range of four to twelve acceptable gait capture trials was collected for each child before therapy began and again after four weeks of treatment. The effects of therapy were significant in four of the lower extremity muscle analyses, three of the temporal parameters, and eighteen of the spatial parameters. All muscle lengths showed less deviation from normal values after physical therapy across all subjects. Results of this study support the further evaluation of OpenSim as a tool to improve quantitative assessment of musculoskeletal dynamics during the course of rehabilitative therapy in children using orthotics.

Distribution of segmental foot kinematics in patients with degenerative joint disease of the ankle.

Degenerative joint disease (DJD) of the ankle is a debilitating chronic disease associated with severe pain and dysfunction resulting in antalgic gait alteration. Little information is available about segmental foot and ankle motion distribution during gait in ankle osteoarthritis. The aim of the current study was to dynamically characterize segmental foot and ankle kinematics of patients with severe ankle arthrosis requiring total ankle replacement. This was a prospective study involving 36 (19 M, 17 F) adult patients with a clinical diagnosis of ankle arthrosis ("DJD" group) and 36 (23 M, 13 F) healthy subjects ("Control" group). Motion data were collected at 120 Hz using a 3-D motion camera system at self-selected speed along a 6-m walkway and processed using the Milwaukee Foot Model (MFM). The SF-36 Health Survey and Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot scale were administered to evaluate functional levels. Findings include decreases in walking speed, cadence, stride length and swing phase, and reduced outcomes scores (SF-36 and AOFAS). Multisegemental motion in patients with ankle DJD demonstrates significant changes in foot mechanics characterized by altered segment kinematics and significant reduction in dynamic ROM at the tibia, hindfoot, forefoot, and hallux when compared to controls. The results demonstrate decreased temporal-spatial parameters and low outcomes scores indicative of functional limitations. Statement of clinical significance: Altered segment kinematics and reduced overall range of motion demonstrate how a single joint pathology affects kinematic distribution in the other segments of the foot and ankle and alters patients' overall gait. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:1739-1746, 2018.

Sagittal Subtalar and Talocrural Joint Assessment During Ambulation With Controlled Ankle Movement (CAM) Boots.

BACKGROUND: The purpose of the current study was to determine sagittal plane talocrural and subtalar kinematic differences between barefoot and controlled ankle movement (CAM) boot walking. This study used fluoroscopic images to determine talar motion relative to tibia and calcaneal motion relative to talus. METHODS: Fourteen male subjects (mean age 24.1 ± 3.5 years) screened for normal gait were tested. A fluoroscopy unit was used to collect images at 200 Hz during stance. Sagittal motion of the talocrural and subtalar joints were analyzed barefoot and within short and tall CAM boots. RESULTS: Barefoot talocrural mean maximum plantar and dorsiflexion were 9.2 ± 5.4 degrees and -7.5 ± 7.4 degrees, respectively; short CAM boot mean maximum plantar and dorsiflexion were 3.2 ± 4.0 degrees and -4.8 ± 10.2 degrees, respectively; and tall CAM boot mean maximum plantar and dorsiflexion were -0.2 ± 3.5 degrees and -2.4 ± 5.1 degrees, respectively. Talocrural mean range of motion (ROM) decreased from barefoot (16.7 ± 5.1 degrees) to short CAM boot (8.0 ± 4.9 degrees) to tall CAM boot (2.2 ± 2.5 degrees). Subtalar mean maximum plantarflexion angles were 5.3 ± 5.6 degrees for barefoot walking, 4.1 ± 5.9 degrees for short CAM boot walking, and 3.0 ± 4.7 degrees for tall CAM boot walking. Mean minimum subtalar plantarflexion angles were 0.7 ± 3.2 degrees for barefoot walking, 0.7 ± 2.9 degrees for short CAM boot walking, and 0.1 ± 4.8 degrees for tall CAM boot walking. Subtalar mean ROM decreased from barefoot (4.6 ± 3.9 degrees) to short CAM boot (3.4 ± 3.8 degrees) to tall CAM boot (2.9 ± 2.6 degrees). CONCLUSION: Tall and short CAM boot intervention was shown to limit both talocrural and subtalar motion in the sagittal plane during ambulation. The greatest reductions were seen with the tall CAM boot, which limited talocrural motion by 86.8% and subtalar motion by 37.0% compared to barefoot. Short CAM boot intervention reduced talocrural motion by 52.1% and subtalar motion by 26.1% compared to barefoot. CLINICAL RELEVANCE: Both short and tall CAM boots reduced talocrural and subtalar motion during gait. The short CAM boot was more convenient to use, whereas the tall CAM boot more effectively reduced motion. In treatments requiring greater immobilization of the talocrural and subtalar joints, the tall CAM boot should be considered.

Assessment of Kinematics and Electromyography Following Arthroscopic Single-Tendon Rotator Cuff Repair.

BACKGROUND: The increasing demand for rotator cuff (RC) repair patients to return to work as soon as they are physically able has led to exploration of when this is feasible. Current guidelines from our orthopedic surgery clinic recommend a return to work at 9 weeks postoperation. To more fully define capacity to return to work, the current study was conducted using a unique series of quantitative tools. To date, no study has combined 3-dimensional (3D) motion analysis with electromyography (EMG) assessment during activities of daily living (ADLs), including desk tasks, and commonly prescribed rehabilitation exercise. OBJECTIVE: To apply a quantitative, validated upper extremity model to assess the kinematics and muscle activity of the shoulder following repair of the supraspinatus RC tendon compared to that in healthy shoulders. DESIGN: A prospective, cross-sectional comparison study. SETTING: All participants were evaluated during a single session at the Medical College of Wisconsin Department of Orthopaedic Surgery's Motion Analysis Laboratory. PARTICIPANTS: Ten participants who were 9-12 weeks post-operative repair of a supraspinatus RC tendon tear and 10 participants with healthy shoulders (HS) were evaluated. METHODS: All participants were evaluated with 3D motion analysis using a validated upper extremity model and synchronized EMG. Data from the 2 groups were compared using multivariate Hotelling T2 tests with post hoc analyses based on Welch t-tests. MAIN OUTCOME MEASUREMENTS: Participants' thoracic and thoracohumeral joint kinematics, temporal-spatial parameters, and RC muscle activity were measured by applying a quantitative upper extremity model during 10 ADLs and 3 rehabilitation exercises. These included tasks of hair combing, drinking, writing, computer mouse use, typing, calling, reaching to back pocket, pushing a door open, pulling a door closed, external rotation, internal rotation, and rowing. RESULTS: There were significant differences of the thoracohumeral joint motion in only a few of the tested tasks: comb maximal flexion angle (P = .004), pull door internal/external rotation range of motion (P = .020), reach abduction/adduction range of motion (P = .001), reach flexion/extension range of motion (P = .001), reach extension minimal angle (P = .025), active external rotation maximal angle (P = .012), and active external rotation minimal angle (P = .004). The thorax showed significantly different kinematics of maximal flexion angle during the call (P = .011), mouse (P = .007), and drink tasks (P = .005) between the 2 groups. The EMG data analysis showed significantly increased subscapularis activity in the RC repair group during active external rotation. CONCLUSIONS: Although limited abduction was expected due to repair of the supraspinatus tendon, only a single ADL (reaching to back pocket) had a significantly reduced abduction range of motion. Thoracic motion was shown to be used as a compensatory strategy during seated ADLs. Less flexion of the thorax may create passive shoulder flexion at the thoracohumeral joint in efforts to avoid active flexion. The RC repair group participants were able to accomplish the ADLs within the same time frame and through thoracohumeral joint kinematics similar to those in the healthy shoulder group participants. In summary, this study presents a quantification of the effects of RC repair and rehabilitation on the ability to perform ADLs. It may also point to a need for increased rehabilitation focus on either regaining external rotation strength or range of motion following RC repair to enhance recovery and return to the workforce. LEVEL OF EVIDENCE: III.

Amputee Subject Testing Protocol, Results, and Analysis of a Powered Transtibial Prosthetic Device.

A powered ankle-foot prothesis and its control system were previously designed and built. To evaluate this prosthesis, amputee subject testing was performed. The testing results are analyzed and compared between the powered prosthesis, passive prosthesis, and able-bodied gait. Qualitative comparison showed the prosthesis achieved the design objectives. During stance phase, active ankle moment was generated in the powered prosthesis before push-off to help the amputee walk more naturally. During swing phase, the powered prosthesis was able to move to natural position to achieve foot clearance. However, the prosthesis is slightly under powered compared with the able-bodied ankle.

Biomechanical model to assess injury reduction during impact.

This paper implements a biomechanical model and actual tipover trajectory data to assess the risk of head and neck injuries in standup forklift accidents. Seven accident scenarios were analyzed for right tipover, left tipover and off-dock accidents both with and without a door on the operator compartment. Each model had specific data including human anthropometry and trajectory input into the modeling and analysis software packages, Visual-Safe MAD and MADYMO. For all three accident scenarios, each of the seven biomechanical models was analyzed for Injury Assessment Reference Values (IARVs) including angular velocity (omega, omega), angular acceleration (alpha, alpha), Head Injury Criterion (HIC), Neck Injury Criterion--shear, tension and bending (NIC) and the biomechanical Neck Injury Predictor (N(ij)). The study concluded that, in general, the addition of a door to the standup forklift operator compartment leads to a reduction in injury during tipover and off-dock accidents. The ability to brace for impact is not included in these MADYMO models. Bracing is far more effective with an enclosed compartment provided by a latching rear door.

A fracture risk assessment model of the femur in children with osteogenesis imperfecta (OI) during gait.

Osteogenesis imperfecta (OI) is a heritable bone fragility disorder characterized by skeletal deformities and increased bone fragility. There is currently no established clinical method for quantifying fracture risk in OI patients. This study begins the development of a patient-specific model for femur fracture risk assessment and prediction based on individuals' gait analysis data, bone geometry from imaging and material properties from nanoindentation (Young's modulus=19 GPa, Poisson's ratio=0.3). Finite element models of the femur were developed to assess fracture risk of the femur in a pediatric patient with OI type I. Kinetic data from clinical gait analysis was used to prescribe loading conditions on the femoral head and condyles along with muscle forces on the bone's surface. von Mises stresses were analyzed against a fracture strength of 115 MPa. The patient with OI whose femur was modeled showed no risk of femoral fracture during normal gait. The highest stress levels occurred during the mid-stance and loading responses phases of gait. The location of high stress migrated throughout the femoral diaphysis across the gait cycle. Maximum femoral stress levels occurred during the gait cycle phases associated with the highest loading. The fracture risk (fracture strength/von Mises stress), however, was low. This study provides a relevant method for combining functional activity, material property and analytical methods to improve patient monitoring.

Muscle force sensitivity of a finite element fracture risk assessment model in osteogenesis imperfecta - biomed 2009.

Osteogenesis imperfecta (OI) is a heritable bone fragility disorder characterized by skeletal deformities and increased bone fragility. There is currently no established clinical method for quantifying fracture risk in OI patients. A method for developing a finite element model of the femur to assist in fracture risk assessment of a selected patient with OI type I was created. The material properties were based on nanoindentation testing of OI bone specimens collected during routine surgery. Dynamic data from clinical gait analysis was used to prescribe joint reaction forces and moments in a quasi-static model. Muscle forces were prescribed according to current literature. Von Mises stresses were analyzed across all seven phases of the gait cycle and analyzed for sensitivity to changes in muscle forces. The model showed that the patient with OI was not at current risk for fracture during normal gait. The highest stress levels occurred during mid stance and loading response. Maximum von Mises stresses were most sensitive to the gluteal muscles. Insight provided by the model may be useful for similar clinical applications, more refined model development and an improved ability for fracture prediction.