A pilot study of the eccentric decline squat in the management of painful chronic patellar tendinopathy. (2004)

Abstract
OBJECTIVES:
This non-randomised pilot study investigated the effect of eccentric quadriceps training on 17 patients (22 tendons) with painful chronic patellar tendinopathy.

METHODS:
Two different eccentric exercise regimens were used by subjects with a long duration of pain with activity (more than six months). (a) Nine consecutive patients (10 tendons; eight men, one woman; mean age 22 years) performed eccentric exercise with the ankle joint in a standard (foot flat) position. (b) Eight patients (12 tendons; five men, three women; mean age 28 years) performed eccentric training standing on a 25 degrees decline board, designed to increase load on the knee extensor mechanism. The eccentric training was performed twice daily, with three sets of 15 repetitions, for 12 weeks. Primary outcome measures were (a) 100 mm visual analogue scale (VAS), where the subject recorded the amount of pain during activity, and (b) return to previous activity. Follow up was at 12 weeks, with a further limited follow up at 15 months.

RESULTS:
Good clinical results were obtained in the group who trained on the decline board, with six patients (nine tendons) returning to sport and showing a significantly reduced amount of pain over the 12 week period. Mean VAS scores fell from 74.2 to 28.5 (p = 0.004). At 15 months, four patients (five tendons) reported satisfactory results (mean VAS 26.2). In the standard squat group the results were poor, with only one athlete returning to previous activity. Mean VAS scores in this group were 79.0 at baseline and 72.3 at 12 weeks (p = 0.144).

CONCLUSION:
In a small group of patients with patellar tendinopathy, eccentric squats on a decline board produced encouraging results in terms of pain reduction and return to function in the short term. Eccentric exercise using standard single leg squats in a similar sized group appeared to be a less effective form of rehabilitation in reducing pain and returning subjects to previous levels of activity.

Diagnosis:  Patellar tendinopathy

Outcome:  VAS score in eccentric decline squat group decreased from 74.2 to 28.5 at 12 weeks with a pain scale at 26.2 in 15 months. In the standard squat group VAS score decreased from 79 to 72.3 at 12 weeks with no follow-up shown at 15 months. 6/8 subjects in the decline group returned to preinjury levels of sports, while only 1/9 in the standard group returned to preinjury levels of pain.

When Assessed:  12 weeks for both groups, 15 months for decline squat group only.

Subjects:  8 men 1 woman, average age 22, in the standard eccentric squat group, and 5 men 3 women, average age 28, in the decline eccentric squat group.

Protocol:  Both groups did eccentric squats 3 sets of 15 reps twice per day, flexing the knee to 90 degrees. The standard squat group did their eccentric squats with their feet flat on the ground while declined group had their feet on a 25-degree decline board intending to increase quadriceps activity and to lessen calf, glute and hamstring activity.

Other Activity:  Most subjects appeared to be athletic, participating in various sports but study did not detail time off of protocol for return to activity in either group.

My Comments:   Results would indicate that you do want to isolate the quadriceps to ensure other muscles are not doing all the work.