Iliotibial band (ITB) pain and biceps femoris pain are often confused as they share similar symptoms especially around the outer knee. Both are seen in active individuals such as runners and cyclists and can cause sharp or achy pain along with a clicking or snapping sensation.
Let’s break down these structures.
What is the ITB?
The ITB is a thick fibrous band – a connective tissue, that runs along the outside of your thigh. It starts at the hip joint (iliac crest) from the glute and tensor fascia latae (TFL) muscles, down into the lateral aspect of the knee. At the knee, the ITB extends out to the knee cap. While it is not a muscle, it does play a crucial role in stabilising the hip and knee during activities such as running, cycling, walking and even climbing stairs.
Through repetitive knee flexion and extension (bending and straightening), this can irritate the ITB at the point where it attaches to the knee. Additionally, recent evidence has suggested that the rotational stability of the knee may contribute. This irritation can cause a sharp pain on the outer aspect of the knee, and pain that tends to be worse when running or climbing stairs. You may also notice a snapping sensation and swelling around the outside of the knee. This is known as ITB syndrome/friction syndrome.
What is the biceps femoris?
The biceps femoris is one of the three muscles that form the hamstring group. It runs from your pelvis (ischial tuberosity) down to the fibular head on the outer part of the knee. It plays a large role in knee flexion and hip extension. The tendon connecting the biceps femoris to the fibula can be irritated or injured due to overload and overuse, leading to tendinopathy. Alongside lateral knee pain, with a biceps femoris tendinopathy you may also experience tenderness, stiffness that improves with movement and aggravation of symptoms with running and walking.
More often than not, clinicians will mistakenly diagnose lateral knee pain as ITB syndrome, rather than a biceps femoris related issue. This is due to the following (not limited to):
- Pain location is almost identical
As mentioned previously, both structures both run and insert into the lateral aspect of the knee. The biceps femoris lies just slightly behind the ITB.
- Similar triggers and activities
Repetitive motion sports such as running, cycling and strength exercises can trigger both conditions. However, the biceps femoris is more likely to be injured in activities such as sprinting and sudden acceleration.
- Incomplete clinical testing
Practitioners may focus more on glute strength and IT band tightness when assessing lateral knee pain, which is biased towards confirming ITB related pain.
- ITB syndrome is more recognised
It is a very common overuse injury that is highly prevalent in runners and cyclists.
How to tell the difference:
- Location of pain on palpation
- ITB syndrome: lateral knee bone, ~2-3cm above the knee joint line
- Biceps femoris tendinopathy: lateral and more posterior
- Provocative tests
- ITB syndrome: Ober’s (and modified Ober’s) or Nobles test.
- Biceps femoris tendinopathy: resisted knee flexion
Treatment
The rehabilitation approach will differ between ITB syndrome and biceps femoris tendon related injuries, which is why it is important through comprehensive assessment to establish the diagnosis early on.
For ITB syndrome, strategies to manage include load management, manual treatments to restore pain-free hip and knee joint range of motion, and strength exercises for muscles that surround the hip and knee.
For biceps femoris tendon tendinopathy, strategies will include load management. However, focus will shift more towards graded exposure of the tendon to different loads, in addition to strengthening other hip and knee muscles.
If you or anyone you know is experiencing pain on the outside of their knee, book in with one of our experienced Physiotherapist’s here at Bend + Mend.
