Anterior Cruciate Ligament Injury

Modalities for Anterior Cruitiate Ligament Injuries


Sara Hall


Hot or Cold?


Cryotherapy (COLD):


Use it Early!
Studies show that cryotherapy, when used < 36 hours of injury for grades 3 & 4 sprains, resulted in earlier return
to activity. For Grade 3 sprains, those who used iced compared to heat recovered almost 4 days earlier. For Grade 4 sprains, those who used ice recovered 17 days earlier than those who used heat.1

During the acute inflammatory phase, cryotherapy reduces edema through vasoconstriction. The metabolic demand of the injured tissues is decreased thus reducing hypoxic damage.2,3
Cold also reduces histamine release and capillary damage. Lymphatic drainage is enhanced by the decrease in pressure on the extravascular fluid.4

Pain relief
Cooling the surface of the skin to around 15°C is believed to inhibit nerve conduction velocity which causes an analgesic effect.5,6

In sub-acute stages:
Cryotherapy produces an analgesic effect during the later stages of inflammation as well which allows for earlier and possibly more rigorous therapeutic exercise.7,8

It is also recommended to use ice in subacute stages after exercising to prevent swelling.9.

Research shows that ice should be applied intermittently for a duration of 10 to 20 minutes.10,11

The use of cold may inhibit muscle spasms and reduce muscle tension. Cryokinetics uses this muscle relaxation to combine motion with the use of cryotherapy.12 ,13

Thermotherapy (HEAT):


One study discusses the application of heat through radiofrequency. This study suggests that collagen shrinks with this type of thermal energy thus resulting in more stability where there was laxity before. The complete outcomes of its use in rehabilitation need further investigation.14

The application of heat softens the underlying and surrounding tissues, which can increase knee range of motion.15

Heat has been shown to decrease the viscosity of the tissues and increase the extensibility of connective tissue. These two factors work to increase joint range of motion.16,17

TENS (Transcutaneous Electrical Nerve Stimulation)


One study suggests that TENS decreases inflammatory pain after inflammation has developed during
acute and chronic phases.18

Another study showed that pain threshold increased when TENS was used on a strong but comfortable setting.19

NMES (Neuromuscular Electrical Stimulation)


NMES along with exercise has been shown to be more effective at improving quadriceps strength than exercise alone after ACL reconstruction.20
Its effect of function and other outcomes is still unknown, though one study said that performance on functional tasks increased.21

NMES and NMES/PEMF (Pulsed Electromagnetic Field Therapy) have both shown to reduce edema after ACL reconstruction. A study also showed that NMES/PEMF produces less pain than NMES alone.22



Application of low intensity ultrasound has been shown to increase the rate of healing at the tendon-bone interface. One study's assumption is that it affects gene expression during the healing process.23

One survey notes that ultrasound is widely used despite the evidence of its effectiveness. Ultrasound was used to "decrease soft tissue inflammation (eg, tendinitis, bursitis) (83.6% of the respondents), increase tissue extensibility (70.9%), enhance scar tissue remodeling (68.8%), increase soft tissue healing (52.5%), decrease pain (49.3%), and decrease soft tissue swelling (eg, edema, joint effusion) (35.1%)".24



Wong et al also addresses the use of phonophoresis. The study reads, "The respondents used US to deliver medication (phonophoresis) for soft tissue inflammation (54.1%), pain management (22.2%), and soft tissue swelling (19.8%)." 23

Water Based Exercise


Exercise in water is uniquely therapeutic for several reasons. Buoyancy decreases gravitational pull on joints and muscles and provides support.25 Warm water relaxes muscles and thus stretching is more comfortable and range of motion can be increased.24 The light pressure of the water surrounding the body reduces swelling and may help increase blood and lymphatic circulation.26 Water resistance can be used in multi-planar directions with limited change in body position. It also provides a support for postural awareness.27

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