Understanding the biomechanical risk factors of
patellofemoral pain (PFP) in military individuals

Alrayani, HHA

Abstract

Patellofemoral pain (PFP) is one of the major sources of chronic knee pain in young athletes,
affecting one in four individuals. To progress further in this field, prospective studies are
therefore needed in order to gain a better understanding of the biomechanical risk factors of
PFP and to develop future treatment and prevention strategies. With this in mind, the main
purpose of the present PhD thesis is to prospectively examine individuals’ lower limb
movements with two-dimensional (2D) video analysis and muscle strength with a handheld
dynamometer (HHD) in order to screen for PFP development, in addition to other lower limb
injuries. Therefore, a systematic review and meta- analysis in addition to three studies were
conducted within this thesis to investigate the factors involved in the development of PFP.
In the first study, 15 healthy subjects (6 male and 9 female) participated in a reliability study
(within-day, between-day, intra-rater, and inter-rater reliability) of 2D frontal plane projection
angle (FPPA) and hip adduction (HADD) angle. They also participated in a validation study
for 2D motion analysis against the gold standard of three-dimensional (3D) motion analysis.
In the second study, eight healthy male subjects participated in a between-day reliability and
validity study for 2D analysis and HHD strength tests against the gold standard of 3D analysis,
using Qualysis Track Manager (QTM) system and an isokinetic dynamometer for the
measurements of lower limb kinematics (FPPA, Q-angle, HADD, knee flexion, ankle
dorsiflexion, and rearfoot angle) and strength (hip abductors and knee extensors). The main
study was undertaken with 315 healthy male infantry cadets and recruits from King Abdul-
Aziz Military Academy (KAMA) and two other basic military training centres in Saudi Arabia.
Lower limb kinematics and muscle strength were measured during running (RUN), single leg
squatting (SLS), and single leg landing (SLL) in the first week of training, and were followed
up over the participants’ 12 weeks of basic military training for the occurrence of PFP and
other lower limb injuries.
Participants who developed PFP had a significantly greater FPPA and Q-angle during SLS,
SLL, and RUN, as well as a significantly greater HADD during SLS and SLL, than participants
who did not develop PFP. In addition, the injured group had significantly lower knee extensor
and hip abductor muscle strength during the baseline assessment when compared to the noninjured
group. The logistic regression revealed that FPPA during SLL significantly predicts the
development of PFP. Therefore, this appears to be a suitable method for screening of PFP risk
before joining basic military training.

Citation

patellofemoral pain (PFP) in military individuals. (Thesis). University of Salford

• Thesis Type: Thesis
• Acceptance Date: Sep 28, 2018
• Deposit Date: Oct 3, 2018
• Publicly Available Date: Oct 3, 2018