This is an excerpt from Postural Correction by Jane C. Johnson.
As the name indicates, in the genu flexum (flexed knee) posture a person bears weight through a knee that is flexed to a greater degree than is normal when standing. Less common than genu recurvatum, it is a posture observed in the elderly or in patients who have been sedentary and their knees have been allowed to rest in a flexed position for prolonged periods. Viewed laterally, an imaginary line drawn vertically from just anterior to the lateral malleolus bisects the tibia longitudinally in normal knee posture (figure 8.6a). In the genu flexum posture the knee itself falls anterior to this line, which no longer bisects the leg (figure 8.6b). This posture is best identified by viewing your client in the sagittal plane, as with the patient in figure 8.6c. Note the increased ankle dorsiflexion commonly associated with this posture.
Figure 8.6 Genu flexum posture: (a) normal knee alignment, (b) knee alignment in genu flexum, and (c) genu flexum of the right leg.
What You Can Do as a Therapist
Caution is needed when attempting to address genu flexum after knee surgery and when working with clients who use wheelchairs or spend much of their time in a chair, such as someone who might be frail or recovering from illness or injury. For each of the techniques suggested, consider whether deep pressure (as might be used when applying soft tissue release or addressing trigger points) is contraindicated for your client; ensure that your client has sufficient balance when performing any standing exercises.
- Recognize that intervention may be limited for clients where genu flexum results from abnormal high tone (e.g., spasticity associated with cerebral palsy).
- Passively release posterior knee tissues using myofascial release technique. This is an ideal technique to use for this posture where tissues on the back of the knee are tensed and pressure into the back of the knee must be avoided because of the presence of the popliteal artery and lymph nodes. A simple cross-hand technique could work well here, with one hand placed superior to the knee and one inferior to it.
- Passively stretch shortened muscles, in this case hamstrings and soleus. There are many ways to do this, including simple stretches held at the end of the existing range (figure 8.7). One of the advantages of this simple supine hamstring stretch is that it can be performed with the knee flexed and, instead of passively flexing the hip at the end of range, ask your client to extend the knee. Contraction of quadriceps will facilitate relaxation of the hamstrings, increasing knee extension without the need for further hip flexion.
Figure 8.7 Therapist techniques for genu flexum include passive stretch of knee flexors.
- Apply massage to encourage a relaxation and lengthening of hamstrings and soleus. This could be deep tissue massage or soft tissue release to address tension you discover localized in specific tissues. Soft tissue release is useful here because it permits you to work within a range of knee flexion postures, stretching localized tissues only as far as is comfortable for your client.
- Treat any trigger points that you find in posterior tissues using localized static pressure and taking care not to press directly into the popliteal space.
- Genu flexum may be secondary to hip flexion (anterior tilt of the pelvis). If your assessments indicate an anteriorly tilted pelvis and shortened hip flexors, treat accordingly using the ideas put forward in chapter 7.
- Using the ideas set out in other sections of this book, treat the altered postures in other joints associated with genu flexum such as foot pronation, medial rotation of the hip, hip hitch and convexity of the spine.
What Your Client Can Do
- Rest in positions likely to stretch the posterior knee tissues. For example, using a footrest, the posterior knee is stretched through gravity (figure 8.8a). It is in the prone position, feet off the couch, and a light weight can be added to the ankle. Take care when using the prone position so as not to injure the front of the knee against the side of the couch or bed. This position is not suitable for clients with patellofemoral conditions when compression of the patella could be aggravating.
- Practice standing knee extension exercises using a stretchy band. Take care that the band is not too narrow because this could press into the back of the knee and cause pain. Active contraction of knee extensors in this manner encourages relaxation in the opposing muscle group, the knee flexors.
- Practice knee extension in supine (figure 8.8b). This is a good starting point for clients with pain or balance issues, for whom the previous exercise may be too demanding. Simply rest comfortably and attempt to press the back of the knee into the bed, floor or treatment couch. Some people place a bolster or small rolled-up towel beneath the ankle to provide leverage.
- Actively stretch the soleus muscle.
- Avoid prolonged sitting where possible unless it is with the legs outstretched and knees extended. If in a seated job, take short breaks and stand every hour to stretch the back of the leg.
- Active soft tissue release can be useful in addressing specific regions of tension in posterior thigh tissues; it is a technique that enables the client to self-treat the knee in flexion.
- Temporarily avoid sports that might perpetuate a flexed knee posture, such as rowing and cycling.
Figure 8.8 Client techniques for genu flexum include letting gravity stretch the posterior tissues in (a) sitting or (b) active knee extension in a supine position.
Learn more about Postural Correction.