BIOMECHANICS & PATHOMECHANICS OF KNEE JOINT AND PATELLOFEMORAL JOINT

Includes detailed description of BIOMECHANICS & PATHOMECHANICS OF KNEE JOINT AND PATELLOFEMORAL JOINT with recent evidences . Hope you find it useful!!

1. BIOMECHANICS & PATHOMECHANICS OF KNEE JOINT AND PATELLOFEMORAL JOINT By:- Dr. Taniya verma ( PT) MPT – Musculoskeletal

2. Content of tibio-femoral joint Articulation surfaces Axial rotations and varus-valgus movt. Menisci Stabilizers Bursae Ligaments and their biomechanics Muscles (quads activity on w.b and n.w.b) TF alignment and wt. bearing forces CKC/OKC – flex/ext on TF joint

3. Knee complex 1.)Tibio-femoral joint 2.)Patello-femoral joint

4. Knee degree of freedom Rotations Flex/Ext – 15° – 140° Varus/Valgus – 6° – 8° in extension Int/ext rotation – 25° – 30° in flexion Translations AP 5 - 10 mm Compression/Distraction 2 - 5 mm Medial/Lateral 1-2mm

5. Tibio-femoral Joint Double condyloid knee joint is also referred to as Medial & Lateral Compartments of the knee. Double condyloid joint with 3 ° freedom of Angular (Rotatory) motion. Flexion/Extension – Plane – Sagittal plane Axis – Coronal axis Medial/lateral (int/ext) rotation – Plane – Transverse plane Axis – Longitudinal axis Abduction/Adduction – Plane – Frontal plane Axis – Antero-posterior axis.

6. Femoral articular surface Femur is proximal articular surface of the knee joint with large medial & lateral condyles. Because of obliquity of shaft, the femoral condyles do not lie immediately below the femoral head but are slightly medial to it. The medial condyle extend further distally, so that, despite the angulation of the femur’s shaft, the distal end of the femur remains essentially horizontal

7. Tibial articulating surface Asymmetrical medial & lateral tibial condyles constitute the distal articular surface of knee joint. Medial tibial plateau is longer in AP direction than lateral The lateral tibial articular cartilage is thicker than the medial side. Tibial plateau slopes posteriorly approx. 7 ° to 10 ° Medial & lateral tibial condyles are separated by two bony spines called the Intercondylar Tubercles

8. Axial rotation of knee arthrokinemetic Axis – vertical axis Plan – transvers plan ROM – Maximum range is available at 90° of knee flexion. The magnitude rotation diminishes as the knee approaches both full extension and full flexion. Medial condyle acts as pivot point while the lateral condyles move through a greater arc of motion, regardless of direction of rotation.

9. Valgus (Abduction)/Varus ( Adduction ) Axis – Antero-posterior axis Plane – Frontal plane ROM – 8 ° at full extension 13 ° with 20 ° of knee flexion. Excessive frontal plane motion could indicate ligamentous insufficiency

10. Menisci of knee joint 2 asymmetrical fibro cartilaginous joint disk called Menisci are located on tibial plateau. The medial meniscus is a semicircle & the lateral is 4/5 of a ring Both menisci are – Open towards intercondylar area Thick peripherally Thin centrally forming cavities for femoral condyle Reduce friction, serve as shock absorber Innervated Menisci removal = increase articular cartilage stress

11. KNEE JOINT STABLIZERS

12. Bursa associated with knee Pre-patellar bursa –located between skin and anterior surface of patella They allows free movement of skin over patella during knee flexion & extension Subcutaneous bursa –Located between patellar ligament & overlying skin. Deep infra-patellar bursa – Located between patellar ligament & tibial tuberosity Helps in reducing friction between the patellar ligament & tibial tuberosity

13. Sub popliteal bursa –located between tendon of the popliteus muscle and the lateral femoral condyle The gastrocnemius bursa - lies between the tendon of the medial head of the gastrocnemius muscle and the medial femoral condyle. The three bursae that are connected to the synovial lining of the joint capsule (the suprapatellar bursa, the sub popliteal bursa, and the gastrocnemius bursa) allow the lubricating synovial fluid to move from recess to recess during flexion and extension of the knee.

14. Ligament of knee joint Collateral ligament Medial collateral ligament (MCL) Lateral collateral ligament (LCL) Cruciate ligament Anterior cruciate ligament (ACL) Posterior cruciate ligament (PCL) Posterior capsular ligament Meniscofemoral ligament Iliotibial band

15. BIOMECHANICS OF ACL Restrains anterior translation of tibia. The ACL consist of two separate bands that wrap around each other.. The anteromedial band (AMB) and the posterolateral band (PLB) With the knee in full extension, the PLB is taut; as knee flexion increases, the PLB loosens and the AMB becomes tight Most injuries occurs in CKC Least stress on ACL between 30°-60° of flexion Anteromedial bundle tight in flexion and extension Posterior lateral bundle tight only in extension

16. The muscles surrounding the knee joint are capable of either inducing or minimizing strain in the ACL. With the tibiofemoral joint in nearly full extension, a quadriceps muscle contraction is capable of generating an anterior shear force on the tibia, thereby increasing stress on the ACL. Fleming et al. reported that the gastrocnemius muscle similarly has the potential to translate the tibia anteriorly and strain the ACL because the proximal tendon of the gastrocnemius wraps around the posterior tibia, effectively pushing the tibia forward when the muscle becomes tense through active contraction or passive stretch 1 . The hamstring muscles are capable of inducing a posterior shear force on the tibia throughout the range of knee flexion, becoming more effective in this role at greater knee flexion angles. The hamstrings, therefore, have the potential to relieve the ACL of some of the stress of checking anterior shear of the tibia on the femur

17. BIOMECHANICS OF PCL Two Bundles- Anteromedial taut in flexion; posteromedial taut In extension Orientation prevents posterior motion of tibia Restraint to varus/valgus force. Restrain motion with knee flexed. Resists rotation especially int.rotation of tibia on femur. The popliteus muscle shares the role of the PCL in resisting posteriorly directed forces on the tibia and can contribute to knee stability when the PCL is absent.

18. Muscles of the Knee Area One-joint Muscle Two-joint Muscle Anterior Vastus Lateralis Rectus Femoris vastus Medialis Vastus Intermedialis Posterior Biceps Femoris (Short) Biceps Femoris (Long) Semimembranosus Semitendinosus Sartorius Gracilis Gastrocnemius Lateral   Tensor Fascia Latae

19. Muscles of Posterior Knee Knee Flexors Semimembranosus, Semitendinosus, Biceps Femoris (Long & Short Heads), Sartorius, Gracilis, Popliteus & Gastrocnemius Muscles Flex + Tibial Medial Rotators Popliteus, Gracilis, Sartorius, Semimembranosus & Semitendinosus Muscles Flex + Tibial Lateral Rotator Biceps Femoris Flex + Abductor Biceps Femoris, Lateral Head Gastrocnemius & Popliteus Flex + Adductor Semimembranosus, Semitendinosus, Medial Head Gastrocnemius, Sartorius & Gracilis

20. Quadriceps muscle Functions – Together, the 4 components of quadriceps femoris muscle function to extend the knee. Rectus femoris being a 2 joint muscle, it also involved in hip flexion along with knee extension. Angle of pull of Quadriceps – Vastus lateralis – Pull 35 ° Lateral to long axis of femur Vastus Intermedius – Pull Parallel to Shaft of femur, making purest knee extensor. Vastus Medialis – Pull depended on segment of muscle – resultant pull 40 ° medially. Upper fibers Vastus Medialis Longus (VML) angled 15 ° – 18 ° Medially Distal fibers Vastus Medialis Oblique (VMO) angled 50 ° – 5 ° Medially

21. When an erect posture is attained – Minimal activity of quadriceps because the LOG passes just anterior to knee axis results in a gravitational extension torque that maintains the joint in extension. In weight-bearing with the knee slightly flexed – The LOG pass posterior to knee joint axis As the gravitational torque tend to promote knee flexion, the activity of quadriceps is necessary to counterbalance the gravitational torque and maintain the knee joint in equilibrium. Quadriceps activities During weight-bearing

22. Quadriceps activities during non–weight-bearing The MA of resistance is minimal when the knee is flexed to 90° but increases as knee extension progresses. Therefore, greater quadriceps force is required as the knee approaches full extension. The opposite happens during weight-bearing activities.

23. TF alignment & weight bearing force The anatomic/ longitudinal axis – Femur – Oblique, directed inferiorly & medially Tibia – Directed vertically The femoral & tibial longitudinal axis form an angle medially at the knee joint of 180 ° – 185 ° In bilateral static stance – equal weight distribution on medial & lateral condyle

24. Deviation in normal force distribution – TF angle > 185 ° – Genu Valgum – compress lateral condyle; increased tensile force on medial condyle TF angle < 175 ° – Genu Varum – compress medial condyle; increased tensile force on lateral condyle Compressive force in dynamic knee joint 2 – 3 time body weight in normal gait 5 – 6 time body weight in activities (like – Running, Stair Climbing etc.)

25. TF CKC Flexion Early 0 ° – 25 ° knee flexion – Posterior rolling of femoral condyles on the tibia. As flexion continues – Posterior Rolling accompanied by simultaneous Anterior glide of femur Create a pure Spin of femur on the posterior tibia

26. TF CKC extension Extension from flexion is a reversal of flexion motion. Early extension – Anterior rolling of femoral condyles on tibial plateau As extension continues – Anterior Rolling accompanied by simultaneous Posterior glide of femur Produce a pure Spin of femoral condyles on tibial plateau Tf OKC flexion / extension When tibia is flexed on a fixed femur – The tibia performed Both Posterior Rolling & Gliding on relatively fixed femoral condyles. When tibia is Extended on a fixed femur – The tibia performed Both Anterior Rolling & Gliding on relatively fixed femoral condyles.

27. Contents of PFJ Articulating surfaces and functions Stabilizers PFJ motions and patellar tracking Contact area of patella during motion PFJ congruence and various patellar positions Joint reaction forces Radiographic evaluation CKC vs OKC and Pt. implications PATELLOFEMORAL PAIN : definition, mechanism, examination and treatment.

28. Articulating surfaces – Patella = inverted triangle with apex directed inferiorly; Articulates with trochlea PFJ function It work primarily as an anatomical pulley It reduce friction between quadriceps tendon & femoral condyle. The ability of patella to perform its function without restricting knee motion depends on its mobility PATELLO-FEMORAL JOINT (PFJ)

29. Patellar Influence on Quadriceps Function Patella lengthens the MA of quadriceps by increasing the distance of quadriceps tendon & patellar tendon from the axis of the knee joint. The patella, as an anatomic pulley, deflects the action line of quadriceps away from the joint centre, increasing the angle of pull & enhancing extension torque generation. Pull of quadriceps also creates anterior translation of tibia on femur increasing ACL restraint Presence of patella allows flexion and extension to occur with a lesser amount of quadriceps force Because the fulcrum (patella) is placed between applied force ( quadriceps) and resistance to be moved (lower leg), patella function as class 1 lever

30. PFJ articulating surface The triangular shape patella is a largest sesamoid bone in body is a least congruent joint too. Posterior surface is divided by a vertical ridge into medial & lateral patellar facets. The ridge is located slightly towards the medial facet making smaller medial facet The medial & lateral facet are flat & slightly convex side to side & top to bottom. At least 30% of patella have 2nd ridge separating medial facet from the extreme medial edge known as Odd Facet of Patella. https://youtu.be/e9MQwjZeQs8

31. Femur patellar surface femoral sulcus/intercondylar groove Corresponds to vertical ridge on patella Concave side to side; convex top to bottom The patella is attached to the tibial tuberosity by the patellar tendon

32. Medial-lateral PFJ stability PFJ is under permanent control of 2 restraining mechanism across each other at right angel. Transvers group of stabilizer Longitudinal group of stabilizer Transvers stabilizer – Medial & lateral retinaculum Vastus Medialis & Lateralis The lateral PF ligament contributes 53% of total force when in full extension of knee. Longitudinal stabilization Patellar tendon – inferiorly Quadriceps tendon – superiorly PATELLO-FEMORAL JOINT STABLIZERS

33. SOFT TISSUE STABLIZERS OF PATELLA Medially= The medial restraints consist of the medial retinaculum, the medial patellofemoral ligament, and the VMO. Laterally= The lateral restraints consist of the lateral retinaculum, the vastus lateralis, and the iliotibial band. Inferiorly = the patella tendon Superiorly = central quadriceps tendon expansion of the quadriceps muscle

34. PATELLAR MOTONS ( patellar tracking) Patellar flexion = patella travels down the intercondylar groove Patellar extension = Knee extension brings the patella back to its original position with the apex of the patella pointing inferiorly Medial and lateral patellar tilt Medial and lateral patellar rotation

35. NORMAL PATELLAR TRACKING Normal tracking of patella inside trochlear groove during knee ROM . Balanced forces around patella = normal biomechanics of PFJ FULL EXTENDED KNEE Patella is tethered in a distal-medial-posterior direction by tight medial retinacula ( MPFL). 0-20’ (trochlear engagement) Medial translation Lateral tilt 4-5 degrees Progressive flexion 20-90 degrees Lateral translation Progressive lateral tilt rotation

36. In full extension- little/no contact b/w femur and patella At 10° – 20° of flexion – contact with inferior margin of medial & lateral facet. By 90° of flexion – all portion of patella contact with femur except the odd facet. Beyond 90° of flexion – medial condyle enter the intercondylar notch & odd facet achieves contact for the first time. At 135° of flexion – contact is on lateral & odd facet with medial facet completely out of contact. CONTACT AREA OF PATELLA ON FEMUR DURING MOTION

37. PFJ congruence Fully extended knee= patella lies on femoral sulcus ; minimal joint congruency The vertical position of patella in femoral sulcus is related to length of patellar tendon, approximately 1:1 is (referred to as Insall-Salvati index) An excessive long tendon produce an abnormally high position of patella on femoral sulcus known as patella alta, (Ratio>1.2) which increases the risk for patellar instability In neutral or extended knee, the patella has little or no contact with the femoral sulcus beneath.

38. Position of patella Patella alta- abnormal high position of patella Patella baja- abnormally low position of patella Squinting of patella- medially facing patella

39. PF joint reaction forces The patella is pulled simultaneously by the quadriceps tendon superiorly and by patella tendon inferiorly In normal full extension the patella is suspended between them Even a strong compression of quads produce no PF compression clinical significance -This is the rational for use of straight leg raising exercise with hip in neutral position as a way of improving quadriceps muscle strength without creating PF problems Minimal quads forces are required during upright and relaxed standing ( COG almost above directly above knee ) As knee flexion increases the COG shift posteriorly, increasing flexion moments required. Knee flexion affects angle between patellar tendon force and quadriceps tendon force The total JRF depends on – 1) magnitude of active or passive pull of quads , 2) angle of knee flexion

40. Medial & lateral force on patella Since the action line of quadriceps & patellar ligament do not co-inside, patella tend to pulled slightly laterally & increase compression on lateral patellar facets. Larger force on patella may cause it to subluxation or dislocate off the lateral lip of femur. Genu valgum increase the obliquity of femur & oblique the pull of quadriceps. Medial Femoral anteversion & lateral tibial torsion = increased obliquity in patella predisposing to excessive lateral pressure or to subluxation or dislocation. Excessive tension in lateral retinaculum (or weakness of VMO) =lateral patellar tilt Insufficient height of lateral lips of femoral sulcus may create patellar subluxation or fully dislocation

41. RADIOGRAPHIC EVALUATION Three views of the patella—an AP, a lateral in 30 degrees of knee flexion, and an axial image—should be obtained. AP view = assess for the presence of any fractures, The overall size, shape, and gross alignment of the patella. lateral view = evaluate the patellofemoral joint space and to look for patella alta or baja, the presence of fragmentation of the tibial tubercle or inferior patellar pole can be seen. Both the AP and the lateral views can also be used to confirm the presence and location of any loose bodies or osteochondral defects that may exist. An axial image, typically a Merchant (knee flexed 45 degrees and x-ray beam angled 30 degrees to axis of the femur) or skyline view , may be the most important. It is used to assess patellar tilt and patellar subluxation

42. SULCUS ANGLE A line is drawn along the medial and lateral walls of the trochlea. The angle formed between them is the sulcus angle. Greater than 150 degrees is abnormal and indicates a shallow or dysplastic groove CONGRUENCE ANGLE Measure Patellofemoral subluxation . The angle is formed by a line drawn from the apex of the trochlear groove bisecting the sulcus angle and a line drawn from the apex of the groove to the apex of the patella. A lateral position of the patella apex relative to the apex of the trochlea is considered positive (with greater positive angles suggesting greater lateral shift) A normal congruence angle has been described as −6 degrees ±6 degrees.

43. (A) sulcus angle (B) congruence angle (C) Lateral displacement may also be quantified by the distance between the medial patellar facet and the apex of the medial femoral condyle. (D) The lateral patellofemoral angle is a measure of patellar tilt and is calculated as the angle between a horizontal line across the peaks of the 2 femoral condyles and a line along the lateral patellar facet. An angle opening medially indicates lateral tilt. (E) The Insall-Salvati index is calculated in the sagittal plane as the ratio of patella length to patellar tendon length. (F) The Blackburne-Peel index similarly quantifies patellar height and is the ratio of the distance of the articular surface of the patella to the distance measured between the inferior patellar articular surface and the tibial plateau.

44. CLOSED KINETIC CHAIN In closed chain mode the joint reaction force on the patellofemoral joint increases as the knee flexes from 0 to 90° The contact area also increases, but the change is less than that of the force. Therefore, the stress in- creases ; as the knee goes from 0 to 90°. From 90 to 120°, the force either Ievels off' or even decreases ;as the quadriceps tendon comes into contact with the trochlea and begins to account for some of the total joint reaction force and contact area.

45. OPEN KINETIC CHAIN In the open chain mode (eg., leg curls and extensions), the forces across the patella are lowest at 90° of flexion . The joint reaction force is quite low. As the knee extends from this flexed position, the quadriceps force increases, the joint reaction force increases (then decreases past 45°). and the contact area progressively decreases. The net result is an increase in contact stress until early flexion (about 25°). Between 5° and 25°, the situation is quite complex At 0 degree, the quadriceps force is high, the joint reaction force is low because the femur and tibia are nearly parallel and because there is no contact between the two cartilaginous surfaces. Likewise, contact stress is low. In hyperextension, the patellar cartilage stress is low because the patella is actually lifted off the distal femur and does not overlap with the trochlea.

46. PHYSICAL THERAPY IMPLICATION Open chain exercises are most safely carried out from 25° to 90° (60° to 90° if there are distal lesions). From a point of view of cartilage stress, straight leg raises with the knee at 0° of extension or hyperextension are equally safe. Closed chain exercises are safest in the 0 to 45° range, especially if there are proximal lesions. Those with patellofemoral pain avoid deep flexion while doing weight-bearing extension exercises and avoid the final 30° of extension during non–weight-bearing knee extension exercises

47. PATELLOFEMORAL PAIN ? (2016 Patellofemoral pain consensus statement ) Diffuse anterior knee pain in activities such as squatting, running, stairs ascend and descend. Patellofemoral pain- synonym for PFP syndrome, chondromalacia patellae, anterior knee pain, runners knee. Pain around or behind the patella increased which is aggravated by at least one activity that loads the patellofemoral joint during weight bearing on a flexed knee (eg, squatting, stair ambulation, jogging/ running, hopping/jumping).

48. PATELLOFEMORAL PAIN –MECHANISM (Christopher M.Powers) Diminished contact area Quadriceps contraction activity ( stair ascent/descent) Inc.. JRF decreased contact area Inc.. PFJ stress Braces reduce symptoms by increasing contact areas. High cartilage and bone stress Loading elevated hydrostatic and shear stress in articular cartilage thinner cartilage reduces deformational behavior. Cartilage stress transfer to sub chondral bone ( innervated- primary source of retropatellar pain ) high bone stress. Patella malalignment/abnormal tracking Trochlear dysplasia /patellar alta excessive lateral patellar tilt lateral displacement decreased contact area increased PFJ stress

49. PROXIMAL FACTORS = Hip related; Excessive knee valgus resulting from hip adduction increased Q angle frontal plane malalignment. Controlled hip adduction reduce laterally directed force on PFJ hence reduced Q angle. Impaired hip strength (extensors, abductors and ER) altered hip mechanics Improved strength controlled hip rotation improved patellar tracking improve contact area. DISTAL FACTORS= related to foot and ankle; Foot pronation and tibial rotation Abnormal foot pronation Inc.. tibial rotation decreased Q angle Foot orthosis- provide short term relief ( 6-8 weeks)

50. Quadriceps; hamstring; gastro soleus flexibility Decreased quadriceps flexibility leads to = Inc. PFJ stress; anterior pelvic tilt; limits gluteal activation Hamstring tightness= Inc. knee flexion; Inc. PFJ stress; limits knee extension and quads activity ( Inc. PF JRF);posterior pelvic tilt Gastro soleus tightness= limited ankle DF mobility; toe out/pronated foot; Inc. tibial IR; Inc. compensatory knee valgus

51. SUBCHONDRAL BONE OVERLOAD THEORY Inc. PFJ stress Inc. cartilage stress Inc. bone stress Inc. patella water content Inc. intra-osmotic pressure PF pain Farrokhi et al.2011 Ho. et al 2014

52. CLINICAL EXAMINATION OF PFP The best available test is anterior knee pain elicited during a squatting manoeuvre: PFP is evident in 80% of people who are positive on this test. Additional tests (limited evidence): Tenderness on palpation of the patellar edges (PFP is evident in 71–75% of people with this finding. Tests with limited diagnostic usefulness ▸ Patellar grinding and apprehension tests (eg, Clarke’s test) have low sensitivity and limited diagnostic accuracy for PFP. ▸ Knee range of motion and effusion

53. Brief physical examination for patellofemoral pain

54. TREATMENT OF PF pain Hip Strengthening as a Treatment  for Patellofemoral Pain Nakagawa et al. ClinRehab, 2009  Fukadaet al. JOSPT, 2010 The combined use of hip and quadriceps  strengthening was better than quadriceps  strengthening alone.

55. Syme, G., Rowe, P., Martin, D., & Daly, G. (2009). Disability in patients with chronic patellofemoral pain syndrome: A randomised controlled trial of VMO selective training versus general quadriceps strengthening. prospective single blind RCT to compare the effects of rehabilitation with VMO VS general strengthening of the quadriceps femoris muscles on pain, function and Quality of Life in patients with PFPS Patients with PFPS were recruited from a hospital orthopaedic clinic and randomised into three groups: (1) physiotherapy with emphasis on selectively retraining the VMO (Selective); (2) physiotherapy with emphasis on general strengthening of the quadriceps femoris muscles (General ); and (3) a no-treatment control group (Control ). The Selective and General groups demonstrated statistically significant and ‘moderate’ to ‘large’ effect size reductions in pain when compared to the Control group. Both the Selective and General groups displayed statistically significant and ‘moderate’ and ‘large’ effect size improvements in subjective function and Quality of Life compared to the Control group

56. ROLE OF VMO : TIME TO RETIRE THE QUADRICEPS IMBALANCE THEORY? Isolated recruitment of the (VMO), has not been proven to occur with exercises commonly prescribed for patellofemoral pain. The concept of VMO strengthening is prefaced on the belief that the VMO can be selectively recruited, independent of the vastus lateralis (VL), through various exercises. A thorough review of the existing literature has revealed that isolated contraction of the VMO independent of the VL has never been documented. Thus, isolated recruitment of the VMO does not occur with commonly prescribed exercises, and that selective strengthening is unlikely.

57. BIOFEEDBACK FOR PFJ PAIN 6 Dursun et al 2 investigated the relationship between biofeedback, exercise, and quadriceps function in patients with PFPS. Sixty subjects participated in the study and were assigned to 1 of the following groups: biofeedback and exercise or exercise only. All subjects performed a traditional exercise program 5 days a week for 4 weeks and then 3 days a week for another 8 weeks. The exercise program consisted of isometric strengthening, as well as Fexibility, proprioceptive, and endurance training. The researchers measured changes in visual-analog-scale (VAS) scores, Functional Index Questionnaire (FIQ) scores, and mean quadriceps contraction at the end of each month. VAS and FIQ scores improved significantly for both groups at each measurement interval Based on these improvements, the authors concluded that biofeedback did not result in clinical improvement beyond that of traditional exercise alone

58. McConnell-Based Patella Taping McConnell 3 has advocated the use of patella taping to promote pain-free exercise for patients with PFPS, reporting that patella taping places the patella in a more medial position and decreases compressive forces caused by excessive lateralization. McConnel has reported success rates as high as 96% in patients with PFPS who performed exercise in combination with this taping technique Eburne and Bannister 4 compared the McConnell regimen with an isometric quadriceps-exercise program in patients with PFPS. One group of subjects performed quadriceps isometric and SLR exercises; subjects in the other group performed VMO-strengthening exercises with McConnell taping. At the end of the 3-month period, subjects in both groups demonstrated improvements in these parameters, and statistical analyses did not reveal any between-group differences. Overall, the showed that both exercise programs benefited all patients by 50%, far less than the 96% success rate reported by McConnell.

59. Clark et al 5 conducted a randomized controlled trial that examined the effect of exercise, patient education, and taping on strength, pain, and function in patients diagnosed with PFPS. The researchers assigned participants to 1 of the following intervention groups: exercise, taping, and education; exercise and education; taping and education; and education regarding the etiology and prevention of further knee irritation (shoe wear, ice, stress relaxation, and diet/weight advice) The researchers measured pain, perceived function, and strength before the intervention and at 3 and 12 months after the beginning of the study. All subjects demonstrated improvements in all parameters at the 3-month retesting period. In addition, those in the exercise and education groups achieved greater strength gains than did subjects who only did taping.

60. PROXIMAL EXERCISES ARE EFFECTIVE IN TREATING PATELLOFEMORAL PAIN SYNDROME: A SYSTEMATIC REVIEW Jeroen S.J. Peters, PT1 and Natalie L. Tyson, PT2 The aim of this systematic review was to investigate the effectiveness of proximal exercises, compared with knee exercises, for patients with patellofemoral pain, in improving pain and function. A computer‐based search (population: patients with patellofemoral pain, intervention: proximal [hip or lumbo‐pelvic] exercises, comparator: knee exercises, outcome: self‐reported pain and/or functional questionnaire) was undertaken. Data was extracted for the exercise prescription and applicable outcome measures, and a descriptive analysis undertaken. Eight studies (three randomized controlled trials, one clinical controlled trial, three cohort studies and one case series) of moderate to high methodological quality met the inclusion criteria. Proximal exercise programs showed a consistent reduction of pain and function in the treatment of patellofemoral pain. All of the proximal exercise programs improved pain and function, while 80% of the knee interventions reduced pain, and 75% improved function.

61. REFERENCES :- Norkins Joint Structure and Function: A Comprehensive Analysis Fourth Edition The Biomechanics of the Patellofemoral joint' -Ronald P. Grelsamer, MD" john R. Klein, MD -' JOSPT 1= Fleming BC, Renstrom PA, Ohlen G, et al.: The gastrocnemius muscle is an antagonist of the anterior cruciate ligament. J Orthop res 2001 2=Electromyographic biofeedback-controlled exercise versus conservative care for patellofemoral pain syndrome. Dursun N1, Dursun E, Kiliç Z. 3=The management of chondromalacia patellae: a long term solution. McCONNELL J. 4=Eburne J, Bannister G. The McConnell regimen versus isometric quadriceps exercises in the management of anterior knee pain. A randomised prospective controlled trial. Knee. 1996;3:151-153 5=Physiotherapy for anterior knee pain: a randomised controlled trial. Clark DI1, Downing N, Mitchell J, Coulson L, Syzpryt EP, Doherty M. 6=Exercise Prescription and Patellofemoral Pain: Evidence for Rehabilitation-in Journal of Sport Rehabilitation Lori Bolgla and Terry Malone