A joint is formed where two bones are joined together, with varying amounts of movement occurring between them. Pain may be related to the structures involved in the function and support of a joint. The hip joint is the joint most commonly related to pain at the front of the hip (Figure 1.1).
The pubic symphysis (Figure 1.5) is the joint where each half of the pelvis joins at the front of the body. The word ͚symphysis simply means – a place where two bones are closely joined. This joint is a flat or plane joint, that includes:
Only very small movements occur at this joint. For example, some rotation occurs during walking, as one side of the pelvis moves slightly forward and the other slightly back, following the movement of the legs.
Pain Related to the Pubic Symphysis
Pubic Symphysis pain is most commonly associated with injury or excess strain due to:
- a major trauma, such as a fall into the splits or a direct impact to the pubic region
- increased stretchiness of the joint ligaments during pregnancy – this is a normal response to hormone changes in preparation for childbirth
- trauma during childbirth – breech delivery, forceps/vacuum delivery
- a gradual build-up of joint stress, such as repetitive movements where the legs move far apart, as may occur in certain sports
- large repetitive forces created by the surrounding muscles, particularly the inner thigh muscles. This is most common in field or court sports that involve changing direction at high speed or kicking.
Pain related to the pubic symphysis is most commonly experienced in the groin region and/or directly over the joint. Groin pain that occurs over the pubic symphysis is referred to as Pubic Related Groin Pain. Other problems may also cause pain in the groin region, so visit our Pain Locator Map to read about different things that may be related to pain here.
Your Hip Pain Professional will assess your pubic pain and examine all the contributing factors. Advice and management approach will be determined by each individuals contributing factors – for example, previous trauma, pregnancy, level of conditioning and athletic involvement.
After a thorough assessment, a Hip Pain Professional will be able to tell you whether changes on your XRays or scans are likely to be related to your pain and what factors could be contributing to the problem. They will also set a plan to help you:
- reduce your pain
- improve your ability to do everyday activities involved with work and the household
- return to sport or modified activity
- look after your hip joints for the long term.
The Sacroiliac Joints
The sacroiliac joints (sometimes abbreviated to SIJs or SI joints) are the joints formed between the two bony wings of the pelvis and the tailbone (sacrum) (Figure 1.6).
- These joints are designed for stability with extremely little movement capacity. They are flat or plane joints though the surfaces of the joint are not completely flat. They are irregular or bumpy to allow some interlocking of the bones for the stability they need.
- They are also surrounded by some of the strongest ligaments in the body. This stable joint structure allows transfer of large forces between the body and the legs during walking, running and jumping.
- Some movement occurs in these joints during walking and running, where one leg is moving forward and the other backward, resulting in a small amount of joint rotation.
- Movement at the sacroiliac joints will also occur during extremes of hip or back motion, although most scientists agree that the amount of movement that occurs at the sacroiliac joints is very small.
Pain Related to the Sacroiliac Joint
Pain and functional difficulties related to the sacroiliac joint:
- most commonly develop during pregnancy or childbirth
- may occur after a major trauma, such as a hard fall onto the bottom or a large force through one leg, for example being dragged by one leg after a fall from a horse or water-skis.
- may develop over time, related to certain types of repetitive forces.
- can develop when there is a problem with the lower back or hip joints, transferring extra load across the sacroiliac joint.
Sacroiliac pain and dysfunction are however, greatly over-diagnosed. While true instability does occur, it is relatively rare and there are many people living unnecessarily in fear, related to a diagnosis of pelvic instability or being told their pelvis keeps moving out of place.
Here are a few facts about the sacroiliac joint that may dispel some of this fear:
- The structure of the sacroiliac joint makes it a very stable joint
- Asymmetry in the human body is normal
- Differences in tightness of the muscles that join on to either side of the pelvis occur naturally, related to leg or arm dominance, sport and occupation. This asymmetry may cause an appearance of asymmetry in the resting position and movement of the pelvis. This is normal and has not been linked to harm.
- Differences in leg length of up to around 1cm are common and normal. Leg length difference may also produce an appearance of asymmetry in pelvic position in standing.
- A click occurring in a joint does not mean it has moved ͚in or out of position. All of us click and pop, some just a little more than others. These are usually normal joint or tendon sounds.
There are also causes for sacroiliac joint pain that are related to other general health conditions. Sacroiliitis refers to an inflammation of the sacroiliac joints associated with a systemic inflammatory disease such as Ankylosing Spondylitis. You can read more about non-musculoskeletal causes of hip and pelvic pain here.
Pain related to the sacroiliac joints is most commonly experienced in the upper buttock region, usually right over the joint, in the area of the dimples at the top of the buttocks. As the pelvis is a ring joined at the front by the pubic symphysis, problems with the sacroiliac joints are sometimes associated with pain in the groin region. There are many other causes for groin pain however, so visit our Pain Locator Map to read about different factors that may be related to pain in each of these regions.
Your Hip Pain Professional will be able to assess your sacroiliac joints to determine if they are likely to be the cause of your pain. If you have sacroiliac joint related pain, you may require:
- advice on modifications to activities or positions – e.g. workplace set-up
- an exercise program to provide optimal muscle support around the joints
- advice regarding short term bracing or taping – only appropriate for short term use and usually only for severe pain and during late stage pregnancy or after trauma
- an injection for short term relief of severe pain, while you work on your rehabilitation
The Sacrococcygeal Joint
- The sacrococcygeal joint is the joint in the tailbone formed between the sacrum and the coccyx (Figure 1.7).
- The coccyx is a small triangular shaped bone made up of 3-5 fused segments. Many ligaments attach to the coccyx helping to provide stability and support for the pelvis, its muscles and contents.
Pain related to the Sacrococcygeal Joint – Coccydynia
Pain relating to the coccyx and sacrococcygeal joint is known as coccydynia (pronounced cox-y-dynia). A sudden onset of coccygeal pain is usually associated with trauma, externally such as from a fall backwards onto the bone, or internally such as in childbirth. Onset can also be gradual, commonly related to sustained pressure from sitting or local muscle forces.
Factors associated with an increased risk of developing coccydynia are:
- being overweight
- being female – women are 5 times more likely to develop the condition
- increased flexibility or mobility of the joint (hypermobility)
- reduced flexibility or stiffness of the joint (hypomobility)
- variants of coccyx shape
- pelvic floor muscle weakness or overactivity
- other general health factors (see other causes section): These must be ruled out.
Your Hip Pain Professional can reduce your pain associated with coccydynia by addressing factors such as:
- excessive weight bearing on the coccyx due to seating or habitual sitting postures
- weakness, spasm or altered activity in the muscles that attach to the coccyx including the gluteus maximus (buttock) and pelvic floor muscles (see the soft tissue section)
- altered stress and strain on the structures that attach to the coccyx which may have occurred after trauma or as a gradual build up over time.
- providing or referring you for a pain-relieving injection into the area or in very rare cases, to a surgeon.