Dissertation submitted in partial compliance with the requirements for the Master's Degree in Technology: Chiropractic, Durban Institute of Technology, 2005 / Patellofemoral Pain Syndrome (PFPS) is a common knee problem that affects 25% of the general population. PFPS generally affects adolescents, especially females, young adults and sports men and women. PFPS is defined as anterior knee pain arising from dysfunction of the patellofemoral articulation including its connective and contractile tissues. Literature suggests an extensor mechanism dysfunction as the most probable etiology. The majority of literature suggests that PFPS is associated with restricted patella motion, especially medial glide, resulting from a tight lateral retinaculum and/or tight iliotibial band. The beneficial effect of patella mobilization in the management of PFPS, suggested by the results of a number of studies, further suggests that restricted patella motion may be an integral feature of PFPS, as a causative and/or perpetuating factor. The purpose of this study was to assess the associations between the severity of PFPS (in terms of the objective and subjective clinical measures) and patella mobility (direction of mobility loss and degree of motion loss). / M

M.Tech.

Total knee arthroplasty is a widely used and relatively successful procedure, designed to relieve pain and restore function to patients suffering from osteoarthritis. However, satisfaction following the procedure is low. One of the primary sources of pain and a cause of functional limitations following knee arthroplasty is the patellofemoral joint. Reasons for pain in the patellofemoral joint are not well understood but adverse patellofemoral biomechanics are thought to contribute. Many in vitro methods exist for the investigation of patellofemoral joint biomechanics but there is no consistent standard protocol. It is therefore difficult to draw any general conclusions regarding the effect of specific design or alignment factors on the biomechanics of the patellofemoral joint. The present study aimed to improve current understanding of factors contributing to patellofemoral complications. A knee simulator, which was based on the Oxford Knee Rig and included synthetic models for a number of soft tissue and bony structures, was developed. The simulator was demonstrated to provide a simplified but physiologically relevant model of the human knee, which allowed effective assessment of patellofemoral joint biomechanics under physiological loads. The system eliminated the need for cadaveric tissue and therefore demonstrated reduced variability, enabling the efficient assessment of a number of potentially influencing factors. A number of investigations were carried out using the simulator to assess the effect of patella component design and position, and femoral component alignment on patellofemoral biomechanics using the Scorpio NRG system. The results of these studies indicate the benefit of medialisation of the apex of the patella component and warn against excessive femoral component sagittal plane malalignment. However, in general they indicated the relatively forgiving nature of the Scorpio system to malalignment and highlighted that irrespective of alignment and patella component design, pressures in excess of material limits are frequently achieved in deep flexion.

Background Patellofemoral pain (PFP) is a common musculoskeletal complaint with inadequate long term outcomes. We aimed to review current evidence relating to tailored interventions, address knowledge gaps concerning how tailoring should best be delivered and establish whether such interventions are feasible. This thesis investigated whether the interaction of hip and foot biomechanics better explains PFP presentation and management, and could be used to inform feasibility studies of delivering tailored interventions for individuals with this recalcitrant condition. Methods Two systematic reviews with meta-analysis identified predictors of conservative management outcomes and the effects and mechanisms of proximal rehabilitation interventions. A reliability study tested a battery of clinical measures, designed to identify biomechanical deficits common in individuals with PFP. An observational study of individuals with PFP investigated possible biomechanical mechanisms of effect for in shoe foot orthoses. A case control study design explored the electromyographic activity of the gluteal region during common rehabilitation exercises. A randomised intervention trial implemented a tailored intervention to determine feasibility. Results Outcome predictors for conservative management are currently at a derivation stage of development. A clinical battery of 14 measures showed good intra and inter rater reliability for the assessment of lower limb biomechanics. Proximal rehabilitation, combined with quadriceps, achieves favourable outcomes in the short and medium term. Gluteal muscle electromyographic activity is comparable between symptomatic and asymptomatic individuals, with specific exercises achieving desired activation patterns. Tailored intervention using biomechanical characteristics, within a randomised trial, is feasible for recruitment and retention. Conclusion Interventions directed proximal and distal to the patellofemoral joint are effective in the management of PFP. Indicators of treatment success are at a derivation stage,with findings from this thesis providing a comprehensive clinical test battery for lower limb biomechanical assessment. Feasibility of a biomechanically determined tailored intervention has been established.with findings from this thesis providing a comprehensive clinical test battery for lower limb biomechanical assessment. Feasibility of a biomechanically determined tailored intervention has been established.

Thesis (M.S.E.S.)--University of Toledo, 2009. / Typescript. "Submitted as partial fulfillment of the requirements for The Master of Science degree in Exercise Science." "A thesis entitled"--at head of title. Bibliography: leaves 57-61.

Thesis (Ph.D.)--University of Delaware, 2009. / Principal faculty advisor: Irene S. Davis, Dept. of Physical Therapy. Includes bibliographical references.

Thesis (M.S.)--University of British Columbia, 2003. / Includes bibliographical references (leaves 94-97).

A research report submitted to the Faculty of Health Sciences, University of the Witwatersrand, in partial fulfillment of the requirements for the degree of Master of Science in Medicine in the field of Biokinetics Johannesburg, 2017 / Background: Patellofemoral pain (PFP) is a common knee complaint associated with pain around the patella. Research has identified altered electromyographic (EMG) activity of the knee muscles in individuals with PFP compared to a healthy population (Briani et al., 2016). Purpose: The purpose of this observational study was to identify the EMG activity of the quadriceps muscle during functional activities in participants experiencing PFP and participants with no PFP. Methods: The onset and sequence timing including the ranking and Q-angle in relation to the rectus femoris (RF), vastus medialis obliquus (VMO) and vastus lateralis (VL) activity was measured with surface EMG in 17 PFP participants and 17 controls during a sit to stand, squat, and step up and step down. Results: The RM-ANOVA discovered a significant difference in the onset of VMO compared to RF muscle between the activities in the PFP group (-0.11 to 0.07 sec; p = 0.03) and the healthy group (-0.18 to -0.03; p = <0.01), as well as the VL compared to the RF muscle in the PFP group (-0.07 to 0.13 sec; p = <0.01). Significant differences were shown comparing the ranking of EMG onset for the quadriceps muscle to each activity in the healthy group (p = <0.01 to 0.04), and in the PFP group for the sit to stand (p = 0.01). Onset of VMO activity was predominantly ranked first in the healthy group (56%) and the VL in the PFP group (44%). A Mann-Whitney U-test shown a significant relationship in the healthy group between the Q-angle and the VMO, VL and RF muscles during the step down activity (r = -0.53 to -0.55; p = 0.02 to 0.03). Conclusion: This study confirms that the quadriceps muscle responds differently to different functional activities in the PFP and healthy population respectively. The healthy group tend to utilize the VMO first, compared to the PFP group with altered onset of quadriceps activation. Furthermore, the greater the Q-angle is, the earlier the onset of quadriceps muscle will be in the healthy group. This relationship was not found in the PFP group. / MT2017

BACKGROUND and AIMS. Patellofemoral pain syndrome (PFPS) is complex and challenging musculoskeletal disorder. Maltracking of the patella is considered to be one of the primary causative factors. Vastus Medialis Oblique (VMO) and Vastus Lateralis (VL) muscle imbalance in terms of EMG magnitude and timed onset is implicated in either initiating or perpetuating the patellofemoral pain (Cowan et al, 2002, Witvrouw et al, 1996). Many physiotherapeutic treatments are aimed at addressing this muscle imbalance despite a lack of evidence confirming or refuting it exists and it's association with pain and function. The ultimate aim of the study was therefore to establish if it is appropriate to continue treating muscle imbalance in patients with clinically defined PFPS. OBJECTIVES. The overall objectives of the study were to establish: 1. If VMO-VL muscle imbalance exists in PFPS patients and if so is it specific to this condition or does a similar VMO-VL muscle imbalance exists in a healthy population? 2. If muscle imbalance does exist is it related to clinical symptoms used as indications of pain syndrome in clinical practice? 3. Is muscle imbalance associated with lower limb muscle physiology i.e. lower limb and quadriceps muscle strength in both fresh and fatigued states. METHODS. The study employed a cross-sectional design. 63 patients with patellofemoral pain syndrome (PFPS) and 63 age/sex matched healthy subjects were recruited and VMO & VL normalised EMG RMS amplitude and time onset differences were assessed during functional and experimental tasks. Additionally, correlations with pain level, functional status, muscular flexibility and biomechanical characteristics of the lower limb were explored. RESULTS. The results revealed that the VMO-VL activation patterns are task specific and most significantly related to functional stepping down task at a fast speed of execution (p=0.000). This interesting link between the type of muscle contraction, the speed of execution and the recruitment pattern of the VMO-VL was also confirmed by the non-functional isokinetic eccentric contraction (p=0.000). Additionally, it is the timing of the VMO-VL activation rather the intensity that is important. Also, a correlation appears to exist between activation pattern and duration of symptoms and knee functional performance (p=0.03) but not with the level of pain. CONCLUSION. The findings of the study suggest that the VMO-VL muscle imbalance does exist in a clinically defined PFPS population. Unlike previous studies however, this thesis suggests that specificity of the functional activities and speed of execution have a significant role to play in the muscular performance and it could be argued that this translates to a role in PFPS. It would therefore seem appropriate to continue addressing and treating this complex and challenging issue with physiotherapeutic interventions but this may need to be targeted to interventions that are tailored to addressing issues in relation to stepping down and at fast speed.

The patellofemoral joint (PFJ) is a common source of problems in Orthopaedics and is the source of poorly defined pain and poor function in both normal and replaced knees. Before problems of the PFJ can be fully comprehended a better understanding of the basic form and function of the PFJ is required. The aim of this thesis therefore is to investigate the shape and kinematics of the PFJ and their inter-relations in both normal and replaced knees. The first part of this thesis was concerned with the shape (or form) of the PFJ. Species from the human ancestry over the previous 400 million years were assembled and measurements taken from three dimensional, CT reconstructions, allowing the descriptions of evolutionary changes in the shape, and orientation of the patellofemoral joint in relation to the tibiofemoral compartments. The study chronicled the dramatic changes that occurred in relation to the adoption of the erect bipedal hominin stance which has resulted in varied anatomy at the PFJ, predisposing it to a wide range of pathologies. The articular surface geometry of normal human patellofemoral joints (bone and cartilage) were compared with those of total knee replacements, and patellofemoral joint replacements. Mapping of the trajectory of the apex of the trochlea groove revealed significant differences between native and replaced knees, with the trajectory being orientated laterally in normal knees and either centrally or medially in replaced knees. The second part of this work was concerned with the kinematics (or function) of the PFJ. With current technology it is impossible to measure coronal plane PFJ kinematics with any accuracy in both native and replaced knees. A novel method was developed combining Motion Analysis and UltraSound (MAUS). Validation experiments were undertaken that demonstrated acceptable error (1.8 mm). The MAUS technique was used to show statistically significant differences between the coronal plane kinematics of the patella in normal and replaced knees. In particular in some arthroplasty patients, the patella tracked in the opposite direction to that in normal subjects. The abnormal kinematics were a manifestation of non-anatomical joint replacements. This demonstrates that form and function are closely related. The interaction between form and function in the knee was further investigated using patients with anterior knee pain. Assessment was made of the relationship between patellar subluxation and multiple bony, cartilaginous and soft-tissue factors potentially predisposing to subluxation. The percentage of engagement of the patella in the trochlear groove in knee extension showed the strongest relationship with subluxation, with subjects less than 30% engaged tending to subluxate. This suggests that the most important factor in preventing subluxation is patellar engagement. A clinical study is now required to assess the effect of surgery aimed at improving engagement. The detailed insights into the variability of form and function in the PFJ obtained throughout this thesis will help address pathology in the native knee and guide decisions for new designs of knee replacements. A novel technology has been developed here for measuring patella kinematics which has great potential for future research. The MAUS technique will provide a clinical investigative tool and allow investigation into kinematic abnormalities in other joints.