Gait Analysis with Reference to Chondromalacia Patellae

Transcription

1 /83/ $02.00/0 THE JOURNAL OF ORTHOPAEDIC AND SPORTS PHYSICAL THERAPY Copyright by The Orthopaedic and Sports Physical Therapy Sections of the American Physical Therapy Association Gait Analysis with Reference to Chondromalacia Patellae PAULA Z. DILLON, PT, ATC, MA,* WYNN F. UPDYKE, PHD,* WILLIAM C. ALLEN, MDQ This study analyzed the gait of women exhibiting symptoms of chondromalacia patellae, and compared them with a group of women without chondromalacia symptoms. High speed cinematography was used to film the subjects walking on a level surface and a 15 downhill slope. Flexion of the knee on both surfaces during the single support phase was significantly less for the chondromalacia subjects (P < 0.05). increased external femoral rotation was detected in chondromalacia patellae subjects (P < 0.05) during swing phase on level and sloping surfaces. A radical inward femoral rotation occurred immediately preceding (P < 0.001). We conclude that significant differences in gait are apparent in females exibiting chondromalacia patellae symptoms as compared with apparently normal female knees. Chondromalacia patellae is the softening and degeneration of the articulating surface of the patellae. Symptoms include intermittent pain behind the patellae when exercising, going down stairs, or sitting with the knees flexed for a period of time. physical findings revealed in an examination are pain when the patella is grated against the femur and tenderness during pressure over the articular surface of the patellae.' The etiology is uncertain, but recent theories identify the effects of force on the knee joint and friction against the articular surface of the patella as potential causitive factors. In any attempt to bear weight, gravitational force is generated at the knee, and friction is produced when the muscles of the lower extremity oppose this force. During locomotion, the accumulative force and resulting friction should be reflected in the mechanics of individual walking patterns. The normal gait is regarded as the most efficient method of distributing forces 'Physical Therapist at Deaconess Medical Center, Spokane, WA $ Professor and Chairman, Department of the Professional Curriculum, College of Physical Education, University of Florida, Gainsville, Florida. Presently, Associate Dean, Director of Graduate Studies, School of Health, Physical Education and Recreation, Indiana University, Bloomington, IN Associate Professor of Orthopedics, Shands Medical Center, University of Florida, Gainsville, FL Presently, Professor and Chief of Orthopedics, University of Missouri Medical School, Columbia, MO Partially fulfilled the requirements for the degree of Masters of Arts in Physical Education at the University of Florida, Gainsville, FL with this study. and resultant frictions within the limits of human anatomical structure. The pathology of chondromalacia patellae involves erosion of the underside of the patella at points of articulation with the femur.i4 When this increase friction becomes painful, the patient changes the gait in an attempt to lessen the friction. It is also feasible that chondromalacia may develop due to characteristics of abnormal gait. Instead of chondromalacia influencing the walking pattern, the gait itself may be the cause of the degenerating patellar surface. This study was initiated to analyze and compare by cinematography the gaits of college-age women diagnosed as exhibiting symptoms of chondromalacia patellae with the gait of collegeage women without chondromalacia symptoms. Studies have shown that individuals with normal knees have a similar pattern of ~alking.~ It was hypothesized that a characteristic pathological gait pattern might be detectable in women exhibiting clinical symptoms of chondromalacia patellae. REVIEW OF LITERATURE Research identifies specific differences between normal and pathologic gaits although none has dealt specifically with chondromalacia patellae. Jacobs et al5 found lack of symmetry, lengthened phases, especially the double support

2 phase, and nonuniform rates of force loading and unloading were evident in pathologic gaits. Kettlekamp et al.' reported that in patients with rheumatoid arthritis the knee motion during walking decreased as did cadence and stride length. In a study by Gyory, et al4 flexion and extension at the knee during the stance phase was markedly reduced in patients with rheumatoid arthritis or degenerative joint disease. In patients with rheumatoid arthritis the degree of joint damage and amount of pain reported during weight bearing was proportional to the reduction of stance phase flexion and extension. In the same study, patients with abnormal knees took longer to bear weight, or load the knee at, but unloaded the affected extremity earlier. Decreased flexion and extension at the knee with prolonged loading at was recorded by Suzuke and Tokahama13 in patients with osteoarthritis. Likewise, Kettlekamp7 found average hip and knee motion in patients with rheumatoid arthritis to be decreased in flexion and extension, abduction and adduction, and rotation. These subjects also showed a slow weight acceptance at. According to Gore et ai3, men with surgical hip fusions compensate for absent hip motion by increasing rotation at the pelvis, flexing the knee on the fused side more during the stance phase, and increasing motion in the sound hip. Stauffer et al." demonstrated a positive correlation in pathological gaits between the range of flexion and extension at the knee and maximal isometric hamstring and quadriceps muscle force. Knees supported by stronger muscles had more range of motion in the sagittal plane. Thus, the degree of flexion and extension during gait may be determined by the strength of muscles acting across the knee. Patients in Stauffer's study exhibited limited external and internal rotation at the knee, which could have been due to decreased flexion during gait. Fisk2 observed that degenerative arthritis of the hip causes a loss of internal rotation and extension, thus resulting in a gait associated with rotation of the foot on. METHODS Nineteen college-age female volunteers were subjects in this study. Eight were diagnosed as exhibiting symptoms of chondromalacia patellae, while 11 were symptom-free. The invesigator attempted to match the activity level, height, and weight of the chondromalacia subjects with corresponding values in the normal subjects. All sub- ET AL JOSPT Vol. 5, No. 3 jects signed informed consent statements prior to participation in the study. While walking on a treadmill at a speed of 2.5 miles per hour, subjects were filmed from the front and left side by two high speed cameras operating at 64 frames per second. The subjects were filmed on the level and down a 15O slope. The downhill gait was analyzed because a unique symptom of chondromalacia patellae is pain while descending stairs. The "brake action" of a downhill walking pattern on a treadmill is similar to descending stairs. As subjects became accustomed to treadmill walking, it was more likely that a normal gait would be simulated. Therefore, before the actual filming each subject practiced walking on a level and downhill-sloped treadmill until confidence in treadmill walking was expresed. Small adhesive markers were attached to each subject at anatomical locations to aid in the biomechanical analysis (Fig. 1). The film was analyzed on a Recordak Film Reader and was catagorized according to the following variables: knee flexion and extension, ankle flexion and extension, Fig. 1. Anatomical markings for film analysis.

3 JOSPT NovlDec 1983 CHONDROMALACIA AND GAIT 129 vertical deviation of the anterior superior spine of the ilium, lateral deviation of the lower leg during swing phase, lateral femoral tibia1 angle (anterior view), transverse pelvic rotation, and transverse femoral rotation. The gait of each subject was analyzed for one complete gait cycle, from to the point when the same foot again made contact with the treadmill surface. The distance between the beginning and end points of the gait cycle was interpolated by computer analysis to contain 30 frames. This complete cycle contains four phases of gait. Phase 1 starts with left foot and continues until the opposite (right) foot leaves the ground. During phase 2, the left foot supports the body weight while the right leg swings through. Phase 3 begins with right and continues until phase 4 or the swing phase of the foot. Comparisons were made between the gait of normal and chondromalacia subjects on the basis of frame means 1 through 30, each of which represented a particular point in the gait cycle. By analyzing the overall gait between the normal and symptomatic group, a more distinct picture of the actual gait pattern was obtained. Measurements were made to determine the reliability of the measuring techniques. On the basis of the replotting of randomly selected subjects, the data were found to be consistently accurate within 0.04 centimeters and 2'. Researchers felt that variability of 0.04 centimeters or 2O did not greatly alter the resultant values. Computer analysis was used to determine normal distribution, measures of central tendency, and variability. The t test involving means from independent samples was also utilized to test significant differences between the chondromalacia and normal subject statistics. RESULTS At a P value of 0.05, no significant differences were found between normal and chondromalacia subjects in height, weight, femoral angle, maximum leg girth, maximum thigh girth, femoral length, fibular length, or knee varus or valgus. Differences in gait between subjects with chondromalacia patellae and normal subjects were seen during the single support phases and immediately preceding. Chondromalacia subjects had significantly less flexion at the knee on the level (Fig. 2) during the single support phase (phase 1) (P < 0.05). On the slope, flexion at the knee was decreased in chondromalacia patellae subjects during swing phase on the level and slope (P < 0.05). Also, increased external rotation while the leg was swinging through was followed by a radical internal femoral rotation immediately preceding (P < 0.01) (Fig. 3). Gait patterns expressed by normal subjects in this study were similar to normal patterns demonstrated in other studies.12 No significant differences were seen in the other variables analyzed. DISCUSSION The significant differences between the gaits of normal subjects and subjects with chondromalacia can be attributed to a number of factors. Chondromalacia patellae subjects exhibited less flexion at the knee throughout much of the gait cycle especially during phase 2 when the left leg singularily supports the body weight. The forces at the knee joint while walking can influence the gait. In an analysis of forces transmitted by the knee joint, Morrison8 determined the peak value of force transmitted by the quadricep hamstring muscle groups and gastrocnemius muscle in relation to time. The force transmitted by the left quadriceps was greatest at the beginning of phase 2, just as the left foot began supporting the body weight. In a subsequent study, Morrisong found that the power output of the quadriceps muscle was greater while walking down slope than on the level. The quadricep forces, as determined by Morrison, were greatest at the same point in the gait cycle that chondromalacia patellae subjects in the present study had significantly less flexion at the knee. Because individuals with chondromalacia often feel pain when walking down slopes, this gait may be an adaptation to the effect of these greater forces. In an analysis of knee flexion and extension, Smidt" determined the forces at the patellofemoral joint. As a result of isometric contraction, the compression force at the patellofemoral joint was found to be at least 65 kilograms near complete extension, 128 kilograms at 15" of flexion, 176 kilograms at 30, and in excess of 200 kilograms for 40, 60, 75, and 90' of flexion. Thus, chondromalacia patellae subjects may have a tendency to exhibit less flexion at the knee joint due to the increasing forces at the patellofemoral joint as the knee flexes. The most significant difference between normal and pathologic gaits was the tendency for chondromalacia subjects to exhibit more external rotation of the femur during the swing phase. Then,

4 Phase 1 Phase 2 Phase 3 Phase 4 (double stance) (swing phase (double stance) (wing phase Left foot of right foot) Right foot of left foot) Phase 1 (double stance) Left foot I I I I l I I I I I I I I I I 1 I 1 1 I 1 I 1 ' FRAMES Fig. 2. Knee flexion and extension. Mean frame values. Each frame represents a point in the gait cycle corresponding with the percentage of gait identified above the graph Normal-Level --- CP-Slope Normal-Slope i; 4-01 P s 4-7- FRAMES Fig. 3. femoral rotation. Mean frame values.

5 JOSPT NovlDec 1983 CHONDROMALACIA AND GAIT chondromalacia patellae subjects radically rotated the femur inward just prior to and at (P < 0.001). Once occurred, the chondromalacia subjects again quickly rotated the femur outward. SUMMARY The purpose of this study was to analyze and compare the walking gaits of college-age women diagnosed as exhibiting symptoms of chondromalacia patellae with the gaits of college-age women who were symptom-free. The subjects were 19 college-age women, 11 of whom had normal knees while 8 were symptomatic of chondromalacia patellae. They were filmed by two 16- millimeter cameras (64 frames per second) from the front and side while walking on a level treadmill and at a 15' downhill slope. Chondromalacia subjects were found to have significantly less flexion at the knee on the level and slope during the singular support phase (P < 0.05). Increased outward femoral rotation was detected in chondromalacia subjects during swing phase on the level and slope, and a radical inward femoral rotation occurred in chondromalacia patellae subjects immediately preceding (P < 0.001). ' Appreciation IS expressed to Richard Gajdosik, PT, MS, Director of Physical Theapy, University of Montana and Kathleen Miller, PHD, Professor of Physical Education, University of Montana. Without their motivation and editorial advice thls article would not yet be written. REFERENCES 1. Darracott J, Vernon-Roberts B: The bony changes in chondromalacia patellae. Rheumatol Phys Med X: , Fisk GR: The influence of hip rotation upon the gait. Aust NZ Surg 49:7-12, Gore DR, Murray MP, Sepic SB, et al: Walklng patterns of men with unilateral surgical h~p fusion J Bone Jt Surg 57A: , Gyory AN, Chao EYS, Stauffer RN: Functional evaluation of normal and pathologic knees during gait. Arch Phys Med Rehabil , Jacobs NA, Skorecki J, Charnley J: Analysis of the vertical component of force in normal and pathological gait. J Biomech , Kettlekamp DB, Johnson RJ, Smidt CJ: An electrogoniometric study of knee motion in normal gait. J Bone Jt Surg , Kettlekamp DB, Leaverton PL, Milol S: Gait characteristics of the rheumatoid knee. Arch Surg 104:30-34, Morrison JB: Bio-engineering analysis of force action transmitted by the knee joint. Biomed Eng J 3(3): , Morrison JB: The mechanics of muscle function in locomotion. J. Biomech 3: , Smidt GL: Hip motion and related factors in walking. J Phys Ther 51 :9-12, Stauffer RN, Chao EYS, Gyory AN: Biomechanical gait analysis of the diseased knee joint. Clin Orthop Rel Res , Sutherland D: A measurement of gait movement from motion picture film. J Bone Jt Surg 54A(4): , Suzuke K, Takahama M: Gail patterns of the diseased knee joint. J Jap Orthop 53: , Wiles P, Andrews RS, Devas MD: Chondromalacia patellae. J Bone Jt Surg 48(B):95-113, 1936