Procedure
- The patient’s position depends on the muscle or group of muscles to be tested.
- Examine the muscles by causing them to tense isometrically (without inducing movement of the limb).
- Offer resistance against the force elicited from the patient in response to a request to make a certain movement.
- Enquire about pain. If pain is indicated, compare left and right.
- If necessary, palpate the muscles:
- To determine the muscle tone and the maximum point of pain.
- To differentiate between lipomas and muscle herniations.
- In the case of a suspected avulsion or muscle rupture.
- Initially, it is enough to isometrically test for pain in the different groups of muscles. If the patient indicates pain, separately examine the various muscles of the group of muscles concerned. Have the muscles tensed as selectively as possible.
- The flexors [Figure 63] in particular: the gracilis muscle, sartorius muscle, plantaris muscle, biceps femoris muscle, semitendinosus muscle, semimembranosus muscle and gastrocnemius muscle.
Figure 63
- The extensors [Figure 64] in particular: the rectus femoris muscle, vastus lateralis muscle, vastus medialis muscle and vastus intermedius muscle.
Figure 64
The following muscles can more or less be tested selectively:
- Biceps femoris muscle [Figure 65].
- Function: Flexion and exorotation of the knee, and extension of the hip in particular.
- Disorder: Bursitis and tendonitis at the site of attachment to the fibular head.
Figure 65
Muscle test of the biceps femoris muscle. Flex (less than 90º) and exorotate the knee. Subsequently, in this position give counter resistance in the direction of the knee extension while at the same time instructing the patient to flex their knee.
- Semi-membranosus muscle, semi-tendinosus muscle and gracilis muscle [Figure 66].
- Function: Flexion and endorotation of the knee, extension of the hip in particular (this only applies to the first two muscles stated).
- Disorder: Bursitis at the height of the pes anserinus (superficial and deep).
Figure 66
Muscle test of the semimembranosus muscle, semitendinosus muscle and gracilis muscle. Flex (less than 90º) and endorotate the knee. Subsequently in this position give counter resistance in the direction of the knee extension while at the same time asking the patient to flex the knee.
- Sartorius muscle [Figure 67].
- Function: Flexion of the knee, as well as flexion and exorotation of the hip.
- Disorder: Bursitis at the height of the pes anserinus.
Figure 67
- Gastrocnemius muscle [Figure 68].
- Function: Flexion of the knee, and plantar flexion of the foot in particular (to test this muscle selectively compared to the other knee flexors you can best examine the plantar flexion of the foot when the knee is extended (!); even though by doing this you are also testing the other calf muscles).
- If you want to distinguish the gastrocnemius muscle from the other calf muscles you should subsequently test the plantar flexors with a knee in 90° flexion. The gastrocnemius muscle is far less involved in this starting position.
- Disorder: ‘Whiplash’, rupture of the Achilles tendon.
- NB: It is barely impossible to selectively test the other aforementioned muscles.
Figure 68