Patellofemoral Joint Compressive Forces in Forward and Backward Running

Abstract

T he knee is the most common area of pain in runners, with the patellofemoral joint frequently the joint of dysfunction (10). In adolescents, patellofemoral pain syndrome is the leading cause of chronic knee pain (2). Atrophy of the m t u s medialis oblique muscle is frequently associated with patellofemoral pain syndrome, possibly as a result of the interaction between mechanical and neuromuscular factors (8,12,17). This atrophy is thought to result in extensor mechanism dysfunction, decreased muscle strength, and imbalance in the control between medial and lateral portions of the quadriceps femoris muscle (21). Traditionally, quadriceps strengthening exercises have been used in the rehabilitation of patellofemoral pain syndrome, and more recently, "closed chain" quadriceps strengthening, or quadriceps strengthening in a weight-bearing position, has become an accepted method of treatment (14).Backward running incorporates the "closed chainn concept of quadriceps exercise. Backward running has been documented as increasing quadriceps strength and power (1 1,20). In addition, at self-selected running speeds during the stance phase of backward running, the quadriceps are active for a longer period of stance than during forward running (7). It appears that backward running may be indicated in the rehabilitation of patellofemoral pain syndrome, but the magnitude of the

A comparison of muscle activity and heart rate response during backward and forward walking on an underwater treadmill

“…Secondly, alteration of stride length and frequency may be a possible reason for increased cardiorespiratory response, since it has been shown that stride length is shorter when walking backward than when walking forward [8,12]. Thirdly, when walking backward, the quadriceps muscle acts more concentrically, compared to the more eccentric pattern seen when walking forward [8,11]. Finally, walking backward produces higher blood lactate concentrations than walking forward, thereby suggesting a larger anaerobic component with the former, which may perhaps contribute to a higher cardiorespiratory demand .…”

“…Furthermore, running backward requires a longer period of quadriceps activity and can result in greater quadriceps strength gain than that achieved by running forward on dry land [9,10]. On the other hand, www.elsevier.com/locate/gaitpost Gait & Posture 25 (2007) [222][223][224][225][226][227][228] walking backward on dry land reduces the compressive forces at the patellofemoral joint and decreases force absorption of the knee, due to reduced eccentric function of the quadriceps muscle [11]. Although the eccentric function of quadriceps strength is reduced while walking backward on dry land, it has been found that isometric and concentric quadriceps strength can be maintained [10].…”

Physiological and perceptual responses to backward and forward treadmill walking in water

“…It has been noted that backward locomotion is a beneficial mode of exercise, which could be included in rehabilitation and exercise programs. When compared with forward locomotion, backward locomotion reduces the peak patellofemoral joint compressive forces [3], however, it increases muscle activity [4] and quadriceps strength [5]. Furthermore, backward locomotion has been shown to produce higher cardiopulmonary responses than forward locomotion [6][7][8].…”

The Effects of Graded Forward and Backward Walking on Heart Rate and Oxygen Consumption

“…6,8,12,17 Backward walking has been used as component of rehabilitation programs for many lower-extremity injuries and for injury prevention. 11 Flynn and Soutas-Little 14 reported that backward running could decrease patellofemoral joint reaction forces and decrease eccentric loading of the patellar tendon, decreases that may prove beneficial in treating patients with patellofemoral dysfunction. In terms of knee rehabilitation, backward walking up an incline may be an effective tool to assist with increasing an individual's ability to obtain greater knee flexion during gait.…”