RANGE OF MUSCLE WORK
Kinesiology
FEBRUARY 27, 2017
SCHOOL OF PHYSIOTHERAPY
Kind Edward Medical University
RANGE
Range of muscle work:
The full
range in which a muscle work refers
to the muscle changing from a
position of full stretch and contracting to a position of maximal
shortening.
The full range is divided into parts:
Outer Range
Inner Range
Middle Range
Outer range:
Is from a position where the muscle is
on full stretch to a position half way though the
full range of motion.
Inner range:
Is from a position halfway through the full range to a position
where the muscle is fully shortened.
Middle range:
Is the portion of the full range
between the mid-point of the outer range and
the midpoint of the inner range.
Quadriceps
Large muscle in front of the thigh, the action of which extends the
leg or bends the hip joint
It includes:
Rectus femoris
Vastus lateralis
Vastus medialis
Vastus intermedius
Range of Quadriceps Muscle work
As this muscle group passes so close to the knee joint and attaches just
below it, it can become ‘switched off’ if there is pain or swelling in the
area.
Hip muscles can kick in more and try to help out, and tightness may
develop to prevent instability. It takes a careful assessment to identify
the weakness, as sometimes it is only in part of the movement range
that the weakness is noticed.
For example, patients with patella-femoral pain often identify stair
climbing as their painful activity, and this pain from the cartilage or the
joint can switch off the quadriceps muscles in the middle bending range,
which we use for stair climbing. However, when the knee is fully straight,
the muscle may work pretty well.
In Physiotherapy
The quadriceps muscles are often targeted in physiotherapy exercises
and it is important that they are at full strength after total knee
replacement
ACL repair and if the patient suffers with patella-femoral pain
or problems. If there is a weakness in this muscle group, then problems
can be seen with pain, instability or problem with higher-level functions
such as running and stair climbing or jumping.
Hamstrings
Any of three muscles at the back of the thigh that function to
flex and rotate the leg and extend the thigh .
These are:
Semimembranosus
Semitendinosus
Biceps Femoris
Range of Hamstring Muscle Work
Hamstrings cross over both the hip and knee joints they can act
on the hip or the knee.
The hamstrings flex the knee and also support the pelvis on the
femur in the standing position, therefore resisting forward flexion
of the trunk.
Clinically you normally see 70 to 80 degrees of hip flexion in an
adult when the knee is kept straight (straight leg raise). Children
have closer to 90 degrees.
Our postural habits also contribute to their tightness. In our
sedentary culture we do a lot of sitting and standing.
Sitting maintains our gluteal muscles in a lengthened state
causing them to become weak.
We then must rely more on our hamstrings when standing. When
standing for long periods we shift our hips forward also
disengaging our glutes and our hamstrings must work harder.
